diff --git a/docker/compose-dev.yml b/docker/compose-dev.yml
index 3ed77957..4165ad97 100644
--- a/docker/compose-dev.yml
+++ b/docker/compose-dev.yml
@@ -15,6 +15,7 @@ services:
       GUACD_HOST: "guacd-dev"
       GUACD_TUNNEL_HOST: "termix-dev"
       GUACD_RECORDING_PATH: "/termix-data/session_recordings/guacamole"
+      GUACD_DRIVE_PATH: "/termix-data/rdp-drive"
     depends_on:
       - guacd-dev
     networks:
diff --git a/docker/docker-compose.yml b/docker/docker-compose.yml
index b0d2a850..fda099a7 100644
--- a/docker/docker-compose.yml
+++ b/docker/docker-compose.yml
@@ -12,6 +12,9 @@ services:
       GUACD_HOST: "guacd"
       GUACD_TUNNEL_HOST: "termix"
       GUACD_RECORDING_PATH: "/termix-data/session_recordings/guacamole"
+      # Where guacd stores files for RDP drive redirection (one folder per
+      # user is created underneath). Must be writable by guacd's user.
+      GUACD_DRIVE_PATH: "/termix-data/rdp-drive"
       # Hardened deployments can require keys from environment variables or
       # Docker secrets mounted through JWT_SECRET_FILE, DATABASE_KEY_FILE,
       # ENCRYPTION_KEY_FILE and INTERNAL_AUTH_TOKEN_FILE.
diff --git a/src/backend/hosts/guacamole/drive-settings.ts b/src/backend/hosts/guacamole/drive-settings.ts
new file mode 100644
index 00000000..12baa0ca
--- /dev/null
+++ b/src/backend/hosts/guacamole/drive-settings.ts
@@ -0,0 +1,29 @@
+export const GUACD_DRIVE_PATH_ENV = "GUACD_DRIVE_PATH";
+const DEFAULT_DRIVE_ROOT = "/drive";
+
+/**
+ * Fills in where guacd keeps the files behind RDP drive redirection.
+ *
+ * The folder lives on the guacd host, not on Termix's - with the stock
+ * compose it is a directory in the shared termix-data volume, configured
+ * through GUACD_DRIVE_PATH. Each user gets a folder of their own underneath:
+ * a shared drive would show everyone's uploads to everyone else. A host that
+ * names its own drive-path keeps it.
+ */
+export function withDriveSettings(
+  guacConfig: Record<string, unknown>,
+  userId: string,
+  env: NodeJS.ProcessEnv = process.env,
+): Record<string, unknown> {
+  if (!guacConfig["enable-drive"] || guacConfig["drive-path"]) {
+    return guacConfig;
+  }
+  const root = (
+    env[GUACD_DRIVE_PATH_ENV]?.trim() || DEFAULT_DRIVE_ROOT
+  ).replace(/\/+$/, "");
+  return {
+    ...guacConfig,
+    "drive-path": `${root}/${userId}`,
+    "create-drive-path": true,
+  };
+}
diff --git a/src/backend/hosts/guacamole/routes.ts b/src/backend/hosts/guacamole/routes.ts
index 46acbe97..e5374eda 100644
--- a/src/backend/hosts/guacamole/routes.ts
+++ b/src/backend/hosts/guacamole/routes.ts
@@ -2,6 +2,7 @@ import { getErrorMessage } from "../../utils/error-message.js";
 import express from "express";
 import { GuacamoleTokenService } from "./token-service.js";
 import { withRecordingSettings } from "./recording-settings.js";
+import { withDriveSettings } from "./drive-settings.js";
 import { guacLogger } from "../../utils/logger.js";
 import { AuthManager } from "../../utils/auth-manager.js";
 import { PermissionManager } from "../../utils/permission-manager.js";
@@ -658,10 +659,7 @@ router.post(
 
       switch (connectionType) {
         case "rdp":
-          if (guacConfig["enable-drive"] && !guacConfig["drive-path"]) {
-            guacConfig["drive-path"] = "/drive";
-            guacConfig["create-drive-path"] = true;
-          }
+          guacConfig = withDriveSettings(guacConfig, userId);
           token = tokenService.createRdpToken(
             hostname,
             username,
diff --git a/src/backend/tests/hosts/guacamole/drive-settings.test.ts b/src/backend/tests/hosts/guacamole/drive-settings.test.ts
new file mode 100644
index 00000000..0110f8ed
--- /dev/null
+++ b/src/backend/tests/hosts/guacamole/drive-settings.test.ts
@@ -0,0 +1,34 @@
+import { describe, expect, it } from "vitest";
+import { withDriveSettings } from "../../../hosts/guacamole/drive-settings.js";
+
+describe("withDriveSettings", () => {
+  it("gives each user a folder under GUACD_DRIVE_PATH and creates it", () => {
+    expect(
+      withDriveSettings({ "enable-drive": true }, "user-1", {
+        GUACD_DRIVE_PATH: "/termix-data/rdp-drive/",
+      }),
+    ).toEqual({
+      "enable-drive": true,
+      "drive-path": "/termix-data/rdp-drive/user-1",
+      "create-drive-path": true,
+    });
+  });
+
+  it("falls back to /drive when the environment says nothing", () => {
+    expect(
+      withDriveSettings({ "enable-drive": true }, "user-1", {}),
+    ).toMatchObject({ "drive-path": "/drive/user-1" });
+  });
+
+  it("leaves a host-chosen drive-path alone", () => {
+    const config = { "enable-drive": true, "drive-path": "/mnt/share" };
+    expect(
+      withDriveSettings(config, "user-1", { GUACD_DRIVE_PATH: "/x" }),
+    ).toBe(config);
+  });
+
+  it("does nothing when the drive is not enabled", () => {
+    const config = { "enable-drive": false };
+    expect(withDriveSettings(config, "user-1")).toBe(config);
+  });
+});
diff --git a/src/ui/features/guacamole/GuacamoleFileBrowser.tsx b/src/ui/features/guacamole/GuacamoleFileBrowser.tsx
index b2d58f48..d612f561 100644
--- a/src/ui/features/guacamole/GuacamoleFileBrowser.tsx
+++ b/src/ui/features/guacamole/GuacamoleFileBrowser.tsx
@@ -19,6 +19,7 @@ import {
   parentPath,
   saveBlobAs,
   uploadFile,
+  describeUploadError,
   type RemoteFileEntry,
 } from "./guacamole-filesystem.ts";
 
@@ -76,9 +77,9 @@ export function GuacamoleFileBrowser({
           toast.success(t("guacamole.files.uploaded", { name: file.name }));
         } catch (err) {
           toast.error(
-            err instanceof Error
-              ? err.message
-              : t("guacamole.files.uploadFailed", { name: file.name }),
+            describeUploadError(err, (key) =>
+              t(`guacamole.files.${key}`, { name: file.name }),
+            ),
           );
         } finally {
           setBusyName(null);
diff --git a/src/ui/features/guacamole/guacamole-filesystem.test.ts b/src/ui/features/guacamole/guacamole-filesystem.test.ts
new file mode 100644
index 00000000..55d61eff
--- /dev/null
+++ b/src/ui/features/guacamole/guacamole-filesystem.test.ts
@@ -0,0 +1,20 @@
+import { describe, expect, it } from "vitest";
+import { describeUploadError } from "./guacamole-filesystem";
+
+const t = (key: string) => `#${key}`;
+
+describe("describeUploadError", () => {
+  it("explains guacd's refusal to open the target file as a drive-folder problem", () => {
+    expect(describeUploadError(new Error("FAIL (CANNOT OPEN)"), t)).toBe(
+      "#driveNotWritable",
+    );
+    expect(describeUploadError(new Error("FAIL (NO FS)"), t)).toBe(
+      "#driveUnavailable",
+    );
+  });
+
+  it("passes other messages through and falls back for unknown errors", () => {
+    expect(describeUploadError(new Error("disk full"), t)).toBe("disk full");
+    expect(describeUploadError(undefined, t)).toBe("#uploadFailed");
+  });
+});
diff --git a/src/ui/features/guacamole/guacamole-filesystem.ts b/src/ui/features/guacamole/guacamole-filesystem.ts
index 8ad5be20..5504c047 100644
--- a/src/ui/features/guacamole/guacamole-filesystem.ts
+++ b/src/ui/features/guacamole/guacamole-filesystem.ts
@@ -163,3 +163,22 @@ export function saveBlobAs(blob: Blob, filename: string): void {
   link.click();
   URL.revokeObjectURL(url);
 }
+
+/**
+ * Turns an upload failure into something a user can act on. guacd answers a
+ * refused stream with an ack like "FAIL (CANNOT OPEN)" - accurate, but it
+ * means "the drive folder isn't writable", which is what people need to hear.
+ */
+export function describeUploadError(
+  error: unknown,
+  t: (key: "driveNotWritable" | "driveUnavailable" | "uploadFailed") => string,
+): string {
+  const message = error instanceof Error ? error.message : "";
+  if (/cannot open|can't open|permission denied/i.test(message)) {
+    return t("driveNotWritable");
+  }
+  if (/no fs/i.test(message)) {
+    return t("driveUnavailable");
+  }
+  return message || t("uploadFailed");
+}
diff --git a/src/ui/locales/en.json b/src/ui/locales/en.json
index 4606515f..e5796153 100644
--- a/src/ui/locales/en.json
+++ b/src/ui/locales/en.json
@@ -1952,6 +1952,7 @@
       "uploadFailed": "Failed to upload {{name}}",
       "uploadDisabled": "Uploads are disabled for this connection",
       "driveUnavailable": "Enable RDP drive redirection before uploading files",
+      "driveNotWritable": "guacd cannot write to the drive folder. Check GUACD_DRIVE_PATH (or the host's Drive Path) and its permissions.",
       "dropToUpload": "Drop files to upload"
     },
     "toolbar": {