diff --git a/bucket/concfg.json b/bucket/concfg.json
index 2604ec605..07d6051b4 100644
--- a/bucket/concfg.json
+++ b/bucket/concfg.json
@@ -2,6 +2,6 @@
 	"homepage": "https://github.com/lukesampson/concfg",
 	"version": "0.2013.07.01",
 	"url": "https://github.com/lukesampson/concfg/archive/master.zip",
-	"extract_subdir": "concfg-master",
+	"extract_dir": "concfg-master",
 	"bin": "bin\\concfg.ps1"
 }
\ No newline at end of file
diff --git a/bucket/cowsay.json b/bucket/cowsay.json
index d1ce1f76d..90d85e20f 100644
--- a/bucket/cowsay.json
+++ b/bucket/cowsay.json
@@ -2,6 +2,6 @@
 	"version": "0.2013.07.19",
 	"homepage": "https://github.com/lukesampson/cowsay-psh",
 	"url": "https://github.com/lukesampson/cowsay-psh/archive/master.zip",
-	"extract_subdir": "cowsay-psh-master",
+	"extract_dir": "cowsay-psh-master",
 	"bin": ["cowsay.ps1","cowthink.ps1"]
 }
\ No newline at end of file
diff --git a/bucket/curl.json b/bucket/curl.json
index 597efed89..e80baa2fb 100644
--- a/bucket/curl.json
+++ b/bucket/curl.json
@@ -6,7 +6,7 @@
 		"http://curl.haxx.se/gknw.net/7.30.0/dist-w32/curl-7.30.0-rtmp-ssh2-ssl-sspi-zlib-idn-static-bin-w32.zip",
 		"http://curl.haxx.se/ca/cacert.pem#/curl-ca-bundle.crt"
 	],
-	"extract_subdir": "curl-7.30.0-rtmp-ssh2-ssl-sspi-zlib-idn-static-bin-w32",
+	"extract_dir": "curl-7.30.0-rtmp-ssh2-ssl-sspi-zlib-idn-static-bin-w32",
 	"hash": [
 		"sha256:90af768c246136c14a2ae52e8775fa4d976eda4632159bc565e1a539b4f15e1a",
 		null
diff --git a/bucket/go.json b/bucket/go.json
index ffe363f0e..e6e8b87ea 100644
--- a/bucket/go.json
+++ b/bucket/go.json
@@ -12,7 +12,7 @@
 			"hash": "sha1:dee46d45e27193c14e07e695aa4c13d7fdc9de9b"
 		}
 	},
-	"extract_subdir": "go",
+	"extract_dir": "go",
 	"add_env_path": "bin",
 	"set_env": {
 		"GOROOT": "$dir"
diff --git a/bucket/postgresql.json b/bucket/postgresql.json
index d8bd3faf7..225a50e3e 100644
--- a/bucket/postgresql.json
+++ b/bucket/postgresql.json
@@ -12,7 +12,7 @@
 			"hash": "sha256:26bd5d1555a3c010b0c58a4aaf5e1acd16bcf819926984f0716496d326768502"
 		}
 	},
-	"extract_subdir": "pgsql",
+	"extract_dir": "pgsql",
 	"bin": [
 		"bin\\clusterdb.exe",
 		"bin\\createdb.exe",
diff --git a/bucket/pshazz.json b/bucket/pshazz.json
index 392530025..80f98c5fc 100644
--- a/bucket/pshazz.json
+++ b/bucket/pshazz.json
@@ -1,6 +1,6 @@
 {
 	"version": "0.2013.07.10",
 	"url": "https://github.com/lukesampson/pshazz/archive/master.zip",
-	"extract_subdir": "pshazz-master",
+	"extract_dir": "pshazz-master",
 	"bin": [ "bin\\pshazz.ps1" ]
 }
\ No newline at end of file
diff --git a/bucket/scriptcs.json b/bucket/scriptcs.json
index 116389c48..91f18c256 100644
--- a/bucket/scriptcs.json
+++ b/bucket/scriptcs.json
@@ -3,7 +3,7 @@
 	"version": "0.6.0-alpha-130707",
 	"license": "Apache 2.0",
 	"url": "https://www.myget.org/F/scriptcsnightly/api/v2/package/scriptcs/0.6.0-alpha-130707?fn=/dl.zip",
-	"extract_subdir": "tools\\scriptcs",
+	"extract_dir": "tools\\scriptcs",
 	"hash": "sha256:d0521827f09813cb3e22402e32a0089cf0b425981f3182568c47811717682750",
 	"bin": "scriptcs.exe"
 }
\ No newline at end of file
diff --git a/bucket/vim.json b/bucket/vim.json
index e0e6e5de1..477f5e824 100644
--- a/bucket/vim.json
+++ b/bucket/vim.json
@@ -12,7 +12,7 @@
 		"md5:e16ec5b633d2f00bf511529e6abf3670",
 		"sha256:f6081071fa95a6f49c049e9d2aed2d2a2632ec47635b4b497a97bab5f5add498"
 	],
-	"extract_subdir": "vim\\vim73",
+	"extract_dir": "vim\\vim73",
 	"bin": [ "vim.exe", "vimtutor.ps1" ],
 	"post_install": "if(!(test-path ~\\.vimrc)) {
 		cp \"$(split-path(scoop which vim))\\vimrc_example.vim\" ~\\.vimrc
diff --git a/bucket/winmerge.json b/bucket/winmerge.json
index cdc1d288e..714f3c08f 100644
--- a/bucket/winmerge.json
+++ b/bucket/winmerge.json
@@ -3,6 +3,6 @@
 	"license": "GPL2",
 	"url": "http://downloads.sourceforge.net/project/winmerge/stable/2.14.0/WinMerge-2.14.0-exe.zip",
 	"hash": "sha256:9c77580ff9594536ce84dbbf0095e4b8654892a713989c378b9349c833c0f177",
-	"extract_subdir": "WinMerge-2.14.0-exe",
+	"extract_dir": "WinMerge-2.14.0-exe",
 	"bin": "WinMergeU.exe"
 }
\ No newline at end of file
diff --git a/lib/decompress.ps1 b/lib/decompress.ps1
index 2f9f4cb51..c077137b6 100644
--- a/lib/decompress.ps1
+++ b/lib/decompress.ps1
@@ -7,16 +7,15 @@ function requires_7zip($fname) {
     $fname -match '(\.gz)|(\.tar)|(\.lzma)|(\.7z)$'
 }
 
-function extract_7zip($path, $recurse) {
+function extract_7zip($path, $to, $recurse) {
     if(!$recurse) { write-host "extracting..." -nonewline }
-    $dir = split-path $path
-    $output = 7z x "$path" -o"$dir"
+    $output = 7z x "$path" -o"$to"
     if($lastexitcode -ne 0) { abort "exit code was $lastexitcode" }
 
     # recursively extract files, e.g. for .tar.gz
     $output | sls '^Extracting\s+(.*)$' | % {
         $fname = $_.matches[0].groups[1].value
-        if(requires_7zip $fname) { extract_7zip "$dir\$fname" $true }
+        if(requires_7zip $fname) { extract_7zip "$to\$fname" $to $true }
     }
 
     rm $path
diff --git a/lib/install.ps1 b/lib/install.ps1
index ff0c91ab2..2bac7ad05 100644
--- a/lib/install.ps1
+++ b/lib/install.ps1
@@ -69,7 +69,7 @@ function dl_urls($app, $version, $manifest, $architecture, $dir) {
 			write-host "extracting..." -nonewline
 			# use tmp directory and copy so we can prevent 'folder merge' errors when multiple URLs
 			$null = mkdir "$dir\_scoop_unzip"
-			unzip "$dir\$fname" "$dir\_scoop_unzip" $manifest.extract_subdir
+			unzip "$dir\$fname" "$dir\_scoop_unzip" (extract_dir $manifest $architecture)
 			cp "$dir\_scoop_unzip\*" "$dir" -recurse -force
 			rm -r -force "$dir\_scoop_unzip"
 			rm "$dir\$fname"
@@ -79,7 +79,16 @@ function dl_urls($app, $version, $manifest, $architecture, $dir) {
 				warn "aborting: you'll need to run 'scoop uninstall $app' to clean up"
 				abort "7-zip is required. you can install it with 'scoop install 7zip'"
 			}
-			extract_7zip "$dir\$fname" $manifest.extract_subdir
+			$to = $dir
+			$extract_dir = extract_dir $manifest $architecture
+			if($extract_dir) {
+				$to = "$dir\_scoop_extract"
+			}
+			extract_7zip "$dir\$fname" $to
+			if($extract_dir) {
+				gci "$to\$extract_dir" -r | mv -dest "$dir" -force
+				rm -r -force "$to"
+			}			
 		}
 	}
 
@@ -342,7 +351,7 @@ function rm_env($manifest) {
 		$manifest.set_env | gm -member noteproperty | % {
 			$name = $_.name;
 			env $name $null
-			rm env:\$name
+			if(test-path env:\$name) { rm env:\$name }
 		}
 	}
 }
diff --git a/lib/manifest.ps1 b/lib/manifest.ps1
index 92e749ebf..b851330b9 100644
--- a/lib/manifest.ps1
+++ b/lib/manifest.ps1
@@ -65,4 +65,5 @@ function url($manifest, $arch) { arch_specific 'url' $manifest $arch }
 function installer($manifest, $arch) { arch_specific 'installer' $manifest $arch }
 function uninstaller($manifest, $arch) { arch_specific 'uninstaller' $manifest $arch }
 function msi($manifest, $arch) { arch_specific 'msi' $manifest $arch }
-function hash($manifest, $arch) { arch_specific 'hash' $manifest $arch }
\ No newline at end of file
+function hash($manifest, $arch) { arch_specific 'hash' $manifest $arch }
+function extract_dir($manifest, $arch) { arch_specific 'extract_dir' $manifest $arch}
\ No newline at end of file