Renames to Get-Wix for proper style, and switches to IO.Compression.ZipFile instead of the shell.

Build/GetWix.ps1

@@ -1,18 +1,15 @@
-function GetWix {
+function Get-Wix {
     param($target)
 
     Write-Output "Downloading Wix to $target"
 
     $file = [IO.Path]::GetTempFileName()
-    del $file
-    $file += ".zip"
     Write-Output "  - temporary storage: $file"
 
     Invoke-WebRequest "https://wix.codeplex.com/downloads/get/1421697" -UseBasicParsing -OutFile $file
 
-    $shell = New-Object -COM Shell.Application
-    $dest = $shell.NameSpace("$target")
-    $shell.NameSpace("$file").items() | %{ $dest.CopyHere($_) }
+    [Reflection.Assembly]::LoadWithPartialName('System.IO.Compression.FileSystem') | Out-Null
+    [System.IO.Compression.ZipFile]::ExtractToDirectory($file, $target)
 
     del $file
 }

BuildVSTestHost.ps1

@@ -25,7 +25,7 @@ if ($sign -or $mocksign) {
 
 if (-not (Test-Path $projectDir\Build\Wix\wix.targets)) {
     Import-Module $projectDir\Build\GetWix.ps1 -Force
-    GetWix (mkdir -Force "$projectDir\Build\Wix") -EA Stop
+    Get-Wix (mkdir -Force "$projectDir\Build\Wix") -EA Stop
 }
 
 msbuild $projectDir\Installer\Installer.wixproj `