diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index ee517634..5dfd8287 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -55,13 +55,36 @@ jobs:
             dist/*.tar.gz
             dist/*.zip
 
-      - name: Generate Installers
-        run: |
-          mkdir -p dist-installers
-          ./scripts/generate-installers.sh ./dist-installers
+  installer:
+    name: Windows installers
+    needs: [ build ]
+    runs-on: windows-2022
 
-      - name: Upload Installers
-        uses: actions/upload-artifact@v4
-        with:
-          name: backrest-snapshot-installers
-          path: dist-installers/*.exe
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+
+    - name: Download build artifacts
+      uses: actions/download-artifact@v4
+      with:
+        name: backrest-snapshot-builds
+
+    - name: Unzip artifacts and compile Inno Setup installers
+      shell: powershell
+      run: |
+        mkdir windows_installers
+        foreach ($arch in "x86_64", "arm64") {
+          $src = "backrest_Windows_$arch"
+          Expand-Archive ".\${src}.zip"
+          cp build\windows\* $src
+          & "c:\Program Files (x86)\Inno Setup 6\ISCC.exe" /DArch=$arch ${src}\installer.iss
+          cp "$src\Output\*" windows_installers
+        }
+
+    - name: Upload installers
+      uses: actions/upload-artifact@v4
+      with:
+        name: backrest-snapshot-installers
+        path: windows_installers\*.exe
diff --git a/build/windows/install.nsi b/build/windows/install.nsi
deleted file mode 100644
index 9bea917a..00000000
--- a/build/windows/install.nsi
+++ /dev/null
@@ -1,303 +0,0 @@
-!define BUILD_DIR "."
-!define OUT_DIR "."
-!define APP_NAME "Backrest"
-!define COMP_NAME "garethgeorge"
-!define WEB_SITE "https://github.com/garethgeorge/backrest"
-!define COPYRIGHT "garethgeorge   2024"
-!define DESCRIPTION "${APP_NAME} installer"
-!define LICENSE_TXT "${BUILD_DIR}\LICENSE"
-!define MAIN_APP_EXE "backrest-windows-tray.exe"
-!define INSTALL_TYPE "SetShellVarContext current"
-!define REG_ROOT "HKCU"
-!define REG_UNINSTALL_PATH "Software\Microsoft\Windows\CurrentVersion\Uninstall\${APP_NAME}"
-# Extract version from the changelog.
-!searchparse /file "${BUILD_DIR}\CHANGELOG.md" `## [` VERSION `]`
-# User variables.
-Var UIPort
-Var WelcomeTitle
-Var WelcomeText
-Var WelcomePortNote
-Var OldVersion
-Var Cmd
-Var InstallMode
-Var InstallModeLower
-
-######################################################################
-# Installer file properties
-# NSIS requires X.X.X.X format in VIProductVersion.
-VIProductVersion "${VERSION}.0"
-VIAddVersionKey "ProductName" "${APP_NAME}"
-VIAddVersionKey "CompanyName" "${COMP_NAME}"
-VIAddVersionKey "LegalCopyright" "${COPYRIGHT}"
-VIAddVersionKey "FileDescription" "${DESCRIPTION}"
-VIAddVersionKey "FileVersion" "${VERSION}"
-VIAddVersionKey "ProductVersion" "${VERSION}"
-
-######################################################################
-# Installer settings
-Unicode True
-RequestExecutionLevel user
-SetCompressor LZMA
-Name "${APP_NAME}"
-Caption "$(^Name) ${VERSION} Setup"
-!ifdef ARCH
-OutFile "${OUT_DIR}\Backrest-${ARCH}-setup.exe"
-!else
-OutFile "${OUT_DIR}\Backrest-setup.exe"
-!endif
-XPStyle on
-# Default installation directory.
-InstallDir "$LOCALAPPDATA\Programs\Backrest"
-# If existing installation is detected, use that directory instead.
-InstallDirRegKey "${REG_ROOT}" "${REG_UNINSTALL_PATH}" "UninstallString"
-ManifestDPIAware true
-ShowInstDetails show
-ShowUninstDetails show
-# Include NSIS headers used by this script.
-!include "MUI2.nsh"
-!include "LogicLib.nsh"
-!include "Memento.nsh"
-!include "WordFunc.nsh"
-# Defines for the Memento macro. 
-!define MEMENTO_REGISTRY_ROOT "${REG_ROOT}"
-!define MEMENTO_REGISTRY_KEY "${REG_UNINSTALL_PATH}"
-
-######################################################################
-# GUI pages
-# Prompt to confirm exiting the installer.
-!define MUI_ABORTWARNING
-!define MUI_UNABORTWARNING
-
-!define MUI_WELCOMEPAGE_TITLE "$WelcomeTitle"
-!define MUI_TEXT_WELCOME_INFO_TEXT "$WelcomeText"
-!define MUI_PAGE_CUSTOMFUNCTION_PRE onPreWelcome
-!define MUI_PAGE_CUSTOMFUNCTION_LEAVE onLeaveWelcome
-!insertmacro MUI_PAGE_WELCOME
-
-!insertmacro MUI_PAGE_LICENSE "${LICENSE_TXT}"
-
-!define MUI_COMPONENTSPAGE_NODESC
-!define MUI_COMPONENTSPAGE_TEXT_COMPLIST "Select components to install:$\r$\n$\r$\nSelections will be remembered for future upgrades"
-!define MUI_PAGE_CUSTOMFUNCTION_PRE onPreComponents
-!insertmacro MUI_PAGE_COMPONENTS
-
-!define MUI_PAGE_CUSTOMFUNCTION_PRE onPreDirectory
-!insertmacro MUI_PAGE_DIRECTORY
-
-!insertmacro MUI_PAGE_INSTFILES
-
-!define MUI_FINISHPAGE_RUN "$INSTDIR\${MAIN_APP_EXE}"
-!define MUI_FINISHPAGE_RUN_TEXT "&Start ${APP_NAME} (runs in the system tray)"
-# Use the built-in readme option to open the app URL.
-!define MUI_FINISHPAGE_SHOWREADME http://localhost:$UIPort/
-!define MUI_FINISHPAGE_SHOWREADME_TEXT "&Open Backrest user interface"
-!define MUI_PAGE_CUSTOMFUNCTION_SHOW onShowFinish
-!insertmacro MUI_PAGE_FINISH
-
-# Uninstall pages.
-!define MUI_UNFINISHPAGE_NOAUTOCLOSE
-!insertmacro MUI_UNPAGE_CONFIRM
-!insertmacro MUI_UNPAGE_INSTFILES
-!insertmacro MUI_UNPAGE_FINISH
-
-!insertmacro MUI_LANGUAGE "English"
-
-######################################################################
-# Functions
-# Have to define the function this way to allow re-using it in the uninstall section.
-!macro KillProcess UN
-Function ${UN}KillProcess
-ReadEnvStr $Cmd COMSPEC
-DetailPrint "Stopping Backrest if it is running..."
-# Gracefully attempt to stop Backrest processes for the current user.
-# Do it 5 times, then kill forcefully.
-nsExec::ExecToLog '$Cmd /C echo off & (for /L %i in (1,1,5) do tasklist /FI "USERNAME eq %USERNAME%" | findstr /I /V "setup" | findstr "backrest" && taskkill /FI "USERNAME eq %USERNAME%" /IM "backrest-windows-tray.exe" || exit) & taskkill /FI "USERNAME eq %USERNAME%" /IM "backrest-windows-tray.exe" /F & taskkill /FI "USERNAME eq %USERNAME%" /IM "backrest.exe" /F '
-FunctionEnd
-!macroend
-!insertmacro KillProcess ""
-!insertmacro KillProcess "un."
-
-Function .onInit
-# $R0, $R1 etc are registers; used here as local variables.
-# Read some environment variables.
-ReadEnvStr $Cmd COMSPEC
-ReadEnvStr $R1 BACKREST_PORT
-${If} "$R1" == ""
-  # Use the default port and welcome text if the var is empty.
-  StrCpy $UIPort "9898"
-  StrCpy $WelcomePortNote ""
-${Else}
-  # Extract port number.
-  ${WordFind} "$R1" ":" "+2" $UIPort
-  StrCpy $WelcomePortNote "$\r$\n$\r$\nNOTE: detected BACKREST_PORT environment variable. Will use port $UIPort for shortcuts."
-${EndIf}
-
-# Read the previous Backrest version, if any.
-ReadRegStr $OldVersion ${REG_ROOT} "${REG_UNINSTALL_PATH}" "DisplayVersion"
-${If} "$OldVersion" == "00.00.00.00"
-  # Old pre-1.6.2 installer installed into C:\Program Files; override the default path when upgrading.
-  StrCpy $INSTDIR "$LOCALAPPDATA\Programs\Backrest"
-${EndIf}
-
-${If} "$OldVersion" != ""
-  # Detected existing installation.
-  ${MementoSectionRestore}
-  ${VersionCompare} "$OldVersion" "${VERSION}" $R3
-  ${Select} $R3
-    ${Case} "0"
-      StrCpy $InstallMode "Reinstall"
-    ${Case} "1"
-      StrCpy $InstallMode "Downgrade"
-    ${CaseElse}
-      StrCpy $InstallMode "Upgrade"
-  ${EndSelect}
-  StrCpy $WelcomeTitle "Welcome to ${APP_NAME} $InstallMode"
-  # Convert to lowercase for Welcome text.
-  ${StrFilter} "$InstallMode" "-" "" "" $InstallModeLower
-  StrCpy $WelcomeText "Setup will guide you through the $InstallModeLower of ${APP_NAME} from version $OldVersion to ${VERSION}.$\r$\n$\r$\nInstallation directory is $INSTDIR $WelcomePortNote$\r$\n$\r$\nClick Next to continue."
-${Else}
-  # New installation.
-  # Check if port is already in use and go into the abort mode.
-  nsExec::ExecToStack '$Cmd /C netstat.exe -na | findstr LISTENING | findstr ":$UIPort " '
-  Pop $R4
-  ${If} "$R4" == "0"
-    StrCpy "$InstallMode" "Abort"
-    StrCpy $WelcomeTitle "Error"
-    StrCpy $WelcomeText "*** WARNING ***$\r$\nBackrest binds to port $UIPort for web UI. This port is currently in use by another Backrest instance or another application.$\r$\n$\r$\nPerform the following:$\r$\nClick Start - type $\"environment$\", Enter to open System Properties.$\r$\nClick Environment Variables. Click New in the top section. Enter BACKREST_PORT as the name and 127.0.0.1:port as the value, where $\"port$\" is a number between 1024 and 65535 (avoid known ports; try 9900), then OK 3 times.$\r$\nExit and re-run this installer to have it pick up the new value.$\r$\nSee installation documentation for more details.$\r$\n$\r$\nClick Exit to exit."
-  ${Else}
-    StrCpy $WelcomeTitle "Welcome to ${APP_NAME} Setup"
-    StrCpy $WelcomeText "Setup will guide you through the installation of ${APP_NAME}.$WelcomePortNote$\r$\n$\r$\nClick Next to continue."
-  ${EndIf}
-${EndIf}
-FunctionEnd
-
-Function onPreWelcome
-  ${If} "$InstallMode" == "Abort"
-    # Change text on the button.
-    GetDlgItem $R5 $HWNDPARENT 1
-    ${NSD_SetText} $R5 "&Exit"
-  ${EndIf}
-FunctionEnd
-
-Function onLeaveWelcome
-  ${If} "$InstallMode" == "Abort"
-    Quit
-  ${EndIf}
-FunctionEnd
-
-Function onPreComponents
-  ${If} "$InstallMode" != ""
-    GetDlgItem $R6 $HWNDPARENT 1
-    ${NSD_SetText} $R6 "$(^InstallBtn)"
-  ${EndIf}
-FunctionEnd
-
-Function onPreDirectory
-  # Skip directory page.
-  ${If} "$InstallMode" != ""
-    Abort
-  ${EndIf}
-FunctionEnd
-
-Function onShowFinish
-  # Run custom functions when the checkboxes are clicked.
-  ${NSD_OnClick} $mui.FinishPage.Run onChkRun
-FunctionEnd
-
-Function onChkRun
-  Pop $R7
-  ${NSD_GetState} $mui.FinishPage.Run $7
-  ${If} $7 == ${BST_UNCHECKED}
-    ${NSD_Uncheck} $mui.FinishPage.ShowReadme
-    EnableWindow $mui.FinishPage.ShowReadme 0
-  ${Else}
-    EnableWindow $mui.FinishPage.ShowReadme 1
-  ${EndIf}
-FunctionEnd
-
-Function .onInstSuccess
-  ${MementoSectionSave}
-FunctionEnd
-
-######################################################################
-# Sections
-Section "Application files"
-SectionIn RO
-${INSTALL_TYPE}
-Call KillProcess
-# Clean up remnants from the old installer (except for items in "Program Files" which would require elevation).
-${If} "$OldVersion" == "00.00.00.00"
-  Delete "$DESKTOP\${APP_NAME} Console.lnk"
-  Delete "$SMPROGRAMS\${APP_NAME}\${APP_NAME} Website.lnk"
-  Delete "$SMPROGRAMS\${APP_NAME}\Uninstall ${APP_NAME}.lnk"
-  DeleteRegKey ${REG_ROOT} "Software\Microsoft\Windows\CurrentVersion\App Paths\${MAIN_APP_EXE}"
-${EndIf}
-
-# Allow reinstall and downgrade by overwriting the files.
-SetOverwrite on
-SetOutPath "$INSTDIR"
-File "${BUILD_DIR}\backrest.exe"
-File "${BUILD_DIR}\backrest-windows-tray.exe"
-File "${BUILD_DIR}\LICENSE"
-File "${BUILD_DIR}\icon.ico"
-WriteUninstaller "$INSTDIR\uninstall.exe"
-
-# Start Menu shortcuts.
-CreateDirectory "$SMPROGRAMS\${APP_NAME}"
-CreateShortCut "$SMPROGRAMS\${APP_NAME}\${APP_NAME}.lnk" "$INSTDIR\${MAIN_APP_EXE}" "" "$INSTDIR\icon.ico" 0
-CreateShortCut "$SMPROGRAMS\${APP_NAME}\${APP_NAME} UI.lnk" "http://localhost:$UIPort/" "" "$INSTDIR\icon.ico" 0
-WriteIniStr "$SMPROGRAMS\${APP_NAME}\${APP_NAME} website.url" "InternetShortcut" "URL" "${WEB_SITE}"
-
-# Registry entries.
-WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "DisplayName" "${APP_NAME}"
-WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "UninstallString" "$INSTDIR\uninstall.exe"
-WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "DisplayIcon" "$INSTDIR\icon.ico"
-WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "DisplayVersion" "${VERSION}"
-WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "Publisher" "${COMP_NAME}"
-WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "URLInfoAbout" "${WEB_SITE}"
-WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "InstallLocation" "$INSTDIR"
-SectionEnd
-
-${MementoSection} "Run application at startup (recommended)" sect_startup
-CreateDirectory $SMSTARTUP
-CreateShortcut "$SMSTARTUP\${APP_NAME}.lnk" "$INSTDIR\${MAIN_APP_EXE}" "" "$INSTDIR\icon.ico" 0
-${MementoSectionEnd}
-
-${MementoSection} "Desktop shortcut" sect_desktop
-CreateShortCut "$DESKTOP\${APP_NAME} UI.lnk" "http://localhost:$UIPort/" "" "$INSTDIR\icon.ico" 0
-${MementoSectionEnd}
-${MementoSectionDone}
-
-# If a previous installation created the shortcuts, remove them when user deselects
-# upon upgrade/reinstall to honour the new choice.
-Section "-Remove deselected shortcuts"
-${IfNot} ${SectionIsSelected} ${sect_startup}
-  Delete "$SMSTARTUP\${APP_NAME}.lnk"
-${EndIf}
-${IfNot} ${SectionIsSelected} ${sect_desktop}
-  Delete "$DESKTOP\${APP_NAME} UI.lnk"
-${EndIf}
-SectionEnd
-
-Section "Uninstall"
-${INSTALL_TYPE}
-Call un.KillProcess
-Delete "$INSTDIR\LICENSE"
-Delete "$INSTDIR\icon.ico"
-Delete "$INSTDIR\install.lock"
-Delete "$INSTDIR\restic*.exe"
-Delete "$INSTDIR\backrest.exe"
-Delete "$INSTDIR\backrest-windows-tray.exe"
-Delete "$INSTDIR\uninstall.exe"
-RmDir "$INSTDIR"
-# Delete Start Menu shortcuts.
-Delete "$SMPROGRAMS\${APP_NAME}\${APP_NAME}.lnk"
-Delete "$SMPROGRAMS\${APP_NAME}\${APP_NAME} UI.lnk"
-Delete "$SMPROGRAMS\${APP_NAME}\${APP_NAME} website.url"
-RmDir "$SMPROGRAMS\${APP_NAME}"
-# Startup and desktop shortcuts.
-Delete "$SMSTARTUP\${APP_NAME}.lnk"
-Delete "$DESKTOP\${APP_NAME} UI.lnk"
-# Registry key.
-DeleteRegKey ${REG_ROOT} "${REG_UNINSTALL_PATH}"
-SectionEnd
diff --git a/build/windows/installer.iss b/build/windows/installer.iss
new file mode 100644
index 00000000..bf11718d
--- /dev/null
+++ b/build/windows/installer.iss
@@ -0,0 +1,352 @@
+#define B "Backrest"
+#define TrayExe "backrest-windows-tray.exe"
+#define Website "https://github.com/garethgeorge/backrest/"
+; The following is needed to extract the version from the change log.
+; If the application executable had the version info, then could use built-in GetVersion* functions.
+#define fHandle FileOpen("CHANGELOG.md")
+#expr FileRead(fHandle)
+#expr FileRead(fHandle)
+#define Line FileRead(fHandle)
+#expr FileClose(fHandle)
+#define VStart Pos("[", Line) + 1
+#define VEnd Pos("]", Line)
+#define VLen (VEnd - VStart)
+#define BackrestVersion Copy(Line, VStart, VLen)
+
+[Setup]
+AppName={#B}
+AppVersion={#BackrestVersion}
+AppVerName={#B} {#BackrestVersion}
+AppPublisher=garethgeorge
+AppPublisherURL={#Website}
+VersionInfoVersion={#BackrestVersion}
+DefaultDirName={autopf}\{#B}
+DefaultGroupName={#B}
+DisableProgramGroupPage=yes
+AlwaysShowDirOnReadyPage=yes
+UninstallDisplayIcon={app}\icon.ico
+#ifndef Arch
+  #define Arch "x86_64"
+#endif
+OutputBaseFilename={#B}Setup-{#Arch}
+PrivilegesRequired=lowest
+PrivilegesRequiredOverridesAllowed=dialog
+UsePreviousPrivileges=no
+SetupMutex={#B}Setup
+; Disable built-in RestartManager functionality, see comments under [Files].
+CloseApplications=no
+RestartApplications=no
+#if SameText(Arch, "arm64")
+  #define ArchAllowed "arm64"
+#else
+  #define ArchAllowed "x64os"
+#endif 
+ArchitecturesAllowed={#ArchAllowed}
+ArchitecturesInstallIn64BitMode={#ArchAllowed}
+SetupLogging=yes
+UninstallLogging=yes
+
+[Tasks]
+Name: "adminstartcurrent"; Description: "Run {#B} as the current user. Automatically start when the current user logs in. Inherits user access to network resources. Configuration is stored in the current user profile."; GroupDescription: "Execution context"; Check: IsAdminInstallMode; Flags: exclusive
+Name: "adminstartsystem"; Description: "Run {#B} as the system user. Automatically start before any user logs in. Configuration is stored in the system user profile."; GroupDescription: "Execution context"; Check: IsAdminInstallMode; Flags: exclusive unchecked
+Name: "autostart"; Description: "Automatically start {#B} at log on"; Check: IsUserInstallMode
+Name: "desktopicon"; Description: "Create a desktop icon"; Flags: unchecked
+Name: "addtopath"; Description: "Add {#B} directory to PATH ({code:GetEnvTarget})"; Flags: unchecked
+#define PortDesc "Select a network port for the web interface"
+Name: "port9898"; Description: "Default (9898)"; GroupDescription: "{#PortDesc}"; Flags: exclusive; Check: IsUserInstallMode
+Name: "port9899"; Description: "9899"; GroupDescription: "{#PortDesc}"; Flags: exclusive unchecked; Check: IsUserInstallMode
+Name: "port9900"; Description: "9900"; GroupDescription: "{#PortDesc}"; Flags: exclusive unchecked; Check: IsUserInstallMode
+Name: "port9901"; Description: "9901"; GroupDescription: "{#PortDesc}"; Flags: exclusive unchecked; Check: IsUserInstallMode
+Name: "port9902"; Description: "9902"; GroupDescription: "{#PortDesc}"; Flags: exclusive unchecked; Check: IsUserInstallMode
+
+[Files]
+; Need to stop Backrest not only when uninstalling but also before upgrades or reinstalls
+; This is only an issue when Backrest runs as SYSTEM or non-current user. Inno can natively close applications in other cases,
+; but doing it the same way in all cases for consistency.
+Source: "LICENSE"; DestDir: "{app}"; Flags: ignoreversion; BeforeInstall: StopBackrest
+Source: "icon.ico"; DestDir: "{app}"; Flags: ignoreversion
+Source: "{#TrayExe}"; DestDir: "{app}"; Flags: ignoreversion
+Source: "backrest.exe"; DestDir: "{app}"; Flags: ignoreversion
+
+[Icons]
+; For user install mode only.
+Name: "{autostartup}\{#B} systray"; Filename: "{app}\{#TrayExe}"; Parameters: "{code:GetPortParam}"; IconFilename: "{app}\icon.ico"; Check: IsUserInstallMode
+Name: "{group}\{#B} systray"; Filename: "{app}\{#TrayExe}"; Parameters: "{code:GetPortParam}"; IconFilename: "{app}\icon.ico"; Check: IsUserInstallMode
+; For both modes.
+Name: "{group}\{#B}{code:GetIconSuffix}"; Filename: "http://localhost:{code:GetPort}/"; IconFilename: "{app}\icon.ico"
+Name: "{group}\{#B} website"; Filename: "{#Website}"
+Name: "{autodesktop}\{#B}{code:GetIconSuffix}"; Filename: "http://localhost:{code:GetPort}/"; IconFilename: "{app}\icon.ico"; Tasks: desktopicon
+
+[Messages]
+PrivilegesRequiredOverrideText2=%1 can be installed to run with standard or administrative privileges.%n%nIf you need to use Windows VSS feature with "--use-fs-snapshot" restic option, select the administrative option.%nProtecting Backrest web UI with a password is highly recommended, especially with the administrative install.
+PrivilegesRequiredOverrideAllUsers=Install &system-wide with administrative privileges
+
+[Run]
+; Use Task Scheduler to run Backrest elevated. The 30s delay is needed to avoid an issue with tray icon being broken.
+; The double-quotes escape double-quotes inside the parameter. The backslash escapes double-quotes inside the -Command block.
+Filename: "powershell.exe"; Parameters: "-ExecutionPolicy Bypass -Command ""$t = New-ScheduledTaskTrigger -AtLogOn -User $env:USERNAME ; $t.Delay = 'PT30S'; Register-ScheduledTask -Force -TaskName '{#B}' -RunLevel Highest -Trigger $t -Action $(New-ScheduledTaskAction -Execute \""{app}\{#TrayExe}\"" -Argument '--bind-address 127.0.0.1:9897' -WorkingDirectory '{app}') -Settings $(New-ScheduledTaskSettingsSet -AllowStartIfOnBatteries -ExecutionTimeLimit 0); Start-ScheduledTask -TaskName '{#B}'"" "; Flags: runascurrentuser logoutput runhidden; Tasks: adminstartcurrent; Check: IsAdminInstallMode
+; System user task. No need for systray here, and running it without returning control is the only way to stop it gracefully later.
+Filename: "powershell.exe"; Parameters: "-ExecutionPolicy Bypass -Command ""Register-ScheduledTask -Force -TaskName '{#B}' -RunLevel Highest -User System -Trigger $(New-ScheduledTaskTrigger -AtStartup) -Action $(New-ScheduledTaskAction -Execute \""{app}\backrest.exe\"" -Argument '--bind-address 127.0.0.1:9897' -WorkingDirectory '{app}') -Settings $(New-ScheduledTaskSettingsSet -AllowStartIfOnBatteries -ExecutionTimeLimit 0); Start-ScheduledTask -TaskName '{#B}'"" "; Flags: runascurrentuser logoutput runhidden; Tasks: adminstartsystem; Check: IsAdminInstallMode
+; PATH
+Filename: "powershell.exe"; Parameters: "-ExecutionPolicy Bypass -Command ""$newp = '{app}'; $a = [Environment]::GetEnvironmentVariable('PATH', '{code:GetEnvTarget}') -split ';' ; if ($a -notcontains $newp) {{ echo 'Adding to PATH'; $a += $newp; $path = $a -join ';' ; [Environment]::SetEnvironmentVariable('PATH', $path, '{code:GetEnvTarget}') }"" "; Flags: logoutput runhidden; Tasks: addtopath
+; Remove from PATH for existing installation when unchecked.
+; Reuse the same command in multiple places. Two quotes to escape in preprocessor, two more for the Parameters directive.
+#define PathDelCmd "-ExecutionPolicy Bypass -Command """"$newp = '{app}'; $a = [Environment]::GetEnvironmentVariable('PATH', '{code:GetEnvTarget}') -split ';' ; if ($a -contains $newp) {{ echo 'Removing from PATH'; $path = ($a | Where-Object {{ $_ -ne $newp }) -join ';' ; [Environment]::SetEnvironmentVariable('PATH', $path, '{code:GetEnvTarget}') }"""" "
+Filename: "powershell.exe"; Parameters: "{#PathDelCmd}"; Flags: logoutput runhidden; Tasks: not addtopath; Check: IsExistingInstallation
+
+Filename: "{app}\{#TrayExe}"; Parameters: "{code:GetPortParam}"; Description: "Start {#B} (runs in the system tray)"; Flags: postinstall waituntilidle; Check: IsUserInstallMode
+Filename: "http://localhost:{code:GetPort}/"; Description: "Open {#B} user interface"; Flags: postinstall shellexec
+
+[UninstallRun]
+Filename: "powershell.exe"; Parameters: "{#PathDelCmd}"; Flags: logoutput runhidden; RunOnceId: "RemoveFromPath"
+
+[UninstallDelete]
+Type: files; Name: "{app}\restic*.exe"
+Type: files; Name: "{app}\install.lock"
+; Built-in deletion runs before this section and fails to remove the directory due to the files above.
+Type: dirifempty; Name: "{app}"
+
+[Code]
+var
+  UserInstallationExists, AdminInstallationExists: Boolean;
+  PreviousAdminUser, PreviousAdminTasks, PreviousVersionUser, PreviousVersionAdmin: String;
+  AppName, AppDirAdmin, AppDirUser, RegKey, Cmd: String;
+  
+procedure AssignGlobals();
+begin
+  AppName := ExpandConstant('{#SetupSetting("AppName")}');
+  Cmd := ExpandConstant('{cmd}');
+  RegKey := 'SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\' + AppName + '_is1';
+  if RegQueryStringValue(HKEY_CURRENT_USER, RegKey, 'Inno Setup: App Path', AppDirUser)
+    then UserInstallationExists := True else UserInstallationExists := False;
+  if RegQueryStringValue(HKEY_LOCAL_MACHINE, RegKey, 'Inno Setup: App Path', AppDirAdmin)
+    then AdminInstallationExists := True else AdminInstallationExists := False;
+  RegQueryStringValue(HKEY_CURRENT_USER, RegKey, 'DisplayVersion', PreviousVersionUser)
+  RegQueryStringValue(HKEY_LOCAL_MACHINE, RegKey, 'DisplayVersion', PreviousVersionAdmin)
+  RegQueryStringValue(HKEY_LOCAL_MACHINE, RegKey, 'Inno Setup: Selected Tasks', PreviousAdminTasks);
+  RegQueryStringValue(HKEY_LOCAL_MACHINE, RegKey, 'Inno Setup: User', PreviousAdminUser);
+end;
+
+function IsUserInstallMode(): Boolean;
+begin
+  if IsAdminInstallMode then Result := False else Result := True;
+end;
+
+function GetPort(Param: String): String;
+var
+  S: String;
+  A: array of String;
+  i: Integer;
+begin
+  if IsAdminInstallMode then Result := '9897'
+  else
+  begin
+    A := StringSplit(WizardSelectedTasks(False), [','], stAll);
+    for i := 0 to GetArrayLength(A) - 1 do
+    begin
+      S := A[i];
+      if Pos('port', S) > 0 then StringChangeEx(S, 'port', '', True);
+    end;
+    Result := S;
+  end;
+end;
+
+function GetPortParam(Param: String): String;
+var
+  S: String;
+begin
+  S := GetPort('');
+  // Don't add any shortcut parameters for default port selection.
+  if S = '9898' then Result := '' else Result := '--bind-address 127.0.0.1:' + S;
+end;
+
+function GetIconSuffix(Param: String): String;
+begin
+  if IsAdminInstallMode and UserInstallationExists then Result := ' (system-wide)'
+  else if IsUserInstallMode and AdminInstallationExists then Result := ' (current user)'
+  else Result := '';
+end;
+
+function GetEnvTarget(Param: String): String;
+begin
+  if IsAdminInstallMode then Result := 'Machine' else Result := 'User';
+end;
+
+function IsExistingInstallation(): Boolean;
+begin
+  if UserInstallationExists or AdminInstallationExists then Result := True else Result := False;
+end;
+
+procedure StopBackrest();
+var
+  ResultCode: Integer;
+begin
+  // Attempt to terminate Backrest gracefully for the current user, wait for a second (since taskkill returns immediately),
+  // then check and kill forcefully if it's still running.
+  if IsUserInstallMode then
+    ExecAndLogOutput(Cmd, '/C "taskkill /FI "USERNAME eq %USERNAME%" /IM "backrest-windows-tray.exe" & ping -n 2 127.0.0.1 >nul & tasklist /FI "USERNAME eq %USERNAME%" | findstr /I /V "setup" | findstr "backrest" && (echo Forcing & taskkill /FI "USERNAME eq %USERNAME%" /IM "backrest-windows-tray.exe" /F & taskkill /FI "USERNAME eq %USERNAME%" /IM "backrest.exe" /F)" ',
+    '', SW_HIDE, ewWaitUntilTerminated, ResultCode, nil)
+  // For admin installs stop through the task scheduler. For the SYSTEM or non-current user this is the only way to stop gracefully.
+  // Ending the scheduled task makes a gracefull attempt, then force kills.
+  else if IsAdminInstallMode then
+  begin
+    ExecAndLogOutput(Cmd, '/C schtasks /End /TN ' + AppName + ' || (taskkill /FI "USERNAME eq %USERNAME%" /IM "backrest-windows-tray.exe" /F & taskkill /FI "USERNAME eq %USERNAME%" /IM "backrest.exe" /F)',
+    '', SW_HIDE, ewWaitUntilTerminated, ResultCode, nil);
+    // Remove the task when uninstalling.
+    if IsUninstaller then
+      ExecAndLogOutput(Cmd, '/C schtasks /Delete /TN ' + AppName + ' /F', '', SW_HIDE, ewWaitUntilTerminated, ResultCode, nil);
+  end;
+end;
+
+procedure ShowUpgradeMsg(AppDir: String; InstalledVersion: String);
+var
+  AppVersion, Msg: String;
+  InstalledVersionFull, NewVersionFull: Int64;
+  CompResult: Integer;
+begin
+  AppVersion := ExpandConstant('{#SetupSetting("AppVersion")}');
+  // Convert both old and new versions to the correct type. It also automatically adds '.0' if '0.0.0' format is used.
+  if StrToVersion(InstalledVersion, InstalledVersionFull) and StrToVersion(AppVersion, NewVersionFull) then
+  begin
+    CompResult := ComparePackedVersion(InstalledVersionFull, NewVersionFull);
+    if CompResult < 0 then Msg := 'upgrade'
+    else if CompResult = 0 then Msg := 'reinstall'
+    else if CompResult > 0 then Msg := 'downgrade'
+    else Msg := 'upgrade/reinstall/downgrade';
+  end;
+  MsgBox('Detected existing installation of Backrest ' + InstalledVersion + 
+    ' in ' + Chr(13) + Chr(10) + AppDir + Chr(13) + Chr(10) + Chr(13) + Chr(10) +
+    'Setup will ' + Msg + ' to version ' + AppVersion + '.', mbInformation, MB_OK);
+end;
+
+function NextButtonClick(CurPageID: Integer): Boolean;
+var
+  ResultPortCheck: Integer;
+begin
+  Result := True
+  if CurPageID = wpSelectTasks then
+  begin
+    // Prevent installing an admin instance when a user instance exists under the same user.
+    // It wouldn't work anyway due to the same configuration path.
+    if IsAdminInstallMode and WizardIsTaskSelected('adminstartcurrent') and UserInstallationExists then
+    begin
+      MsgBox('Detected an existing non-administrative installation under the same user ' + GetUserNameString +
+      '. Cannot proceed with this selection.', mbError, MB_OK)
+      Result := False;
+    end
+    else if IsUserInstallMode and not UserInstallationExists then
+    begin
+      if ExecAndLogOutput(Cmd, '/C netstat -na | findstr LISTENING | findstr /C:":' + GetPort('') + ' "', '', SW_HIDE,
+          ewWaitUntilTerminated, ResultPortCheck, nil) and (ResultPortCheck = 0) then
+      begin
+        MsgBox('Selected port is in use, choose another one and try again.', mbError, MB_OK)
+        Result := False;
+      end;
+    end;
+  end;
+end;
+
+procedure RunListClickCheck(Sender: TObject);
+begin
+  if not WizardForm.RunList.Checked[0] then
+  begin
+    WizardForm.RunList.Checked[1] := False;
+    WizardForm.RunList.ItemEnabled[1] := False;
+  end
+  else WizardForm.RunList.ItemEnabled[1] := True;
+end;
+
+procedure CurPageChanged(CurPageID: Integer);
+var
+  i: Integer;
+begin
+  if CurPageID = wpSelectTasks then
+    // Prevent the user from switching installation type back and forth in admin mode.
+    // It would cause issues with terminating processes and also with Backrest data being in different user profiles.
+    if IsAdminInstallMode and AdminInstallationExists then
+      for i := 1 to 2 do WizardForm.TasksList.ItemEnabled[i] := False
+end;
+
+procedure InitializeWizard();
+begin
+  WizardForm.ReadyMemo.ScrollBars := ssVertical;
+  WizardForm.ReadyMemo.WordWrap := True;
+  // Uncheck and disable the "open" checkbox when the "start" is unchecked on the Finish page.
+  if IsUserInstallMode then WizardForm.RunList.OnClickCheck := @RunListClickCheck;
+end;
+
+function InitializeSetup(): Boolean;
+var
+  OldUninstaller: String;
+  I: Integer;
+begin
+  Result := True;
+  AssignGlobals;
+  // Check for presence of the old Nullsoft installation.
+  if RegQueryStringValue(HKEY_CURRENT_USER, 'Software\Microsoft\Windows\CurrentVersion\Uninstall\Backrest',
+    'UninstallString', OldUninstaller) then
+  begin
+    MsgBox('Detected an existing installation done by the old installer that needs to be uninstalled before proceeding. Your configuration will not be impacted.' + Chr(13) + Chr(10) + Chr(13) + Chr(10) +
+    'Re-run this setup after uninstallation is complete.', mbInformation, MB_OK);
+    ExecAsOriginalUser(OldUninstaller, '', '', SW_SHOWNORMAL, ewNoWait, I);
+    Abort;
+  end;
+  // Upgrade/reinstall scenarios.
+  if IsUserInstallMode and UserInstallationExists then ShowUpgradeMsg(AppDirUser, PreviousVersionUser)
+  else if IsUserInstallMode and AdminInstallationExists then
+  begin
+    if GetUserNameString = PreviousAdminUser then
+    begin
+      // Prevent installing a user instance when an admin instance already exists under the same user.
+      MsgBox('Detected an existing administrative installation under the same user ' + PreviousAdminUser + 
+      '. Cannot proceed. Uninstall it and try again. Setup will exit now.', mbError, MB_OK);
+      Result := False;
+    end
+    else begin
+    // But allow and notify about an existing admin instance under a different user, if present.
+      MsgBox('Detected an existing administrative installation of Backrest ' + PreviousVersionAdmin + ' under user ' +
+      PreviousAdminUser + '.' + Chr(13) + Chr(10) + Chr(13) + Chr(10) +
+      'Setup will install a non-administrative instance for the current user.', mbInformation, MB_OK);
+    end;
+  end
+  // Notify the user about the existing installation of the same type, if present.
+  else if IsAdminInstallMode and AdminInstallationExists then 
+  begin
+    ShowUpgradeMsg(AppDirAdmin, PreviousVersionAdmin);
+    // Warn if attempting to upgrade/reinstall under a different user.
+    if (Pos('adminstartcurrent', PreviousAdminTasks) > 0) and (GetUserNameString <> PreviousAdminUser) then
+      MsgBox('Warning! Previous installation of this type was done by user ' + PreviousAdminUser +
+      '. If you proceed, Backrest will be reinstalled to run under the current user. Configuration will be lost.', mbError, MB_OK);
+  end;
+end;
+
+function InitializeUninstall(): Boolean;
+begin
+  Result := True;
+  AssignGlobals;
+  if AdminInstallationExists and UserInstallationExists then
+    MsgBox('Detected two existing installations of Backrest. Ensure you are running the correct uninstaller. Windows Settings - Apps panel shows only one entry at a time.' + Chr(13) + Chr(10) +
+    'Use Control Panel - Programs and Features instead to identify the correct uninstaller. Or run unins000.exe directly from the appropriate Backrest directory.', mbInformation, MB_OK);
+end;
+
+procedure CurUninstallStepChanged(CurUninstallStep: TUninstallStep);
+var
+  BackrestConfig: String;
+begin
+  // Under the system user installation a special profile is used.
+  if IsAdminInstallMode and AdminInstallationExists and (Pos('adminstartsystem', PreviousAdminTasks) > 0) then
+    BackrestConfig := 'C:\Windows\system32\config\systemprofile\AppData\Roaming\backrest'
+  else
+    BackrestConfig := GetEnv('APPDATA') + '\backrest';
+  case CurUninstallStep of
+    usUninstall:
+      StopBackrest;
+    usDone:
+    begin
+      if MsgBox('Do you want to delete Backrest configuration in this location?' + Chr(13) + Chr(10) + BackrestConfig,
+        mbConfirmation, MB_YESNO or MB_DEFBUTTON2) = IDYES then
+        if DelTree(BackrestConfig, True, True, True) then MsgBox('Done!', mbInformation, MB_OK)
+        else MsgBox('Failed to remove the path', mbInformation, MB_OK);
+    end;
+  end;
+end;