How to fix Integration Services when it won't start after patching

# https://support.microsoft.com/en-us/kb/918644

$magicWords = '<generatePublisherEvidence enabled="false"/>'

$dllName = "C:\Windows\Microsoft.NET\Framework\v2.0.50727\MsCorWks.dll"
$dll = [System.Diagnostics.FileVersionInfo]::GetVersionInfo($dllName) # Works on PowerShell v1

# Confirming we have the minimum version of .NET installed
if (!($dll.FileMajorPart -ge 2 -and $dll.FileMinorPart -ge 0 -and $dll.FileBuildPart -ge 50727 -and $dll.FilePrivatePart -ge 876)) {
	Write-Error "$dllName version must be 2.0.50727.876 or higher." 
} else {
	# Find the location of Integration Services, as far as I know only 2005 needs to be patched, which is MsDtsServer
	$service = Get-WmiObject Win32_Service | Where { $_.Name -eq "MsDtsServer" }
	$servicePath = (Split-Path $service.PathName.Replace("`"", ""))
	Set-Location $servicePath
	$files = Get-ChildItem . *.config

	foreach ($file in $files) {
		$okay = $false

		# We should only update the files indicated in the KB article
		switch ($file.Name) {
			"msdtssrvr.exe.config" { 
				$okay = $true
			}
			"DTExec.exe.config" { 
				$okay = $true
			}
			"Dtshost.exe.config" { 
				$okay = $true
			}
			"DtsDebugHost.exe.config" { 
				$okay = $true
			}
			"DTUtil.exe.config" { 
				$okay = $true
			}
			"DTSWizard.exe.config" { 
				$okay = $true
			}
			default {
				$okay = $false
			}
		}
	
		if (!$okay) {
			Write-Host "$($file.Name) does not need to be modified"
		} else {
			$content = Get-Content $file.Name | Out-String

			if ($content -like "*$magicWords*") {
				Write-Host "$($file.Name) is already up to date"
			} else {
				Write-Host "$($file.Name) will be updated"

				# We might need to add some parent tags if they don't exist already. This could be done better with a proper XML parser.
				if ($content -like "*<runtime>*") {
					$content = $content.Replace("</runtime>", "    $magicWords
    </runtime>")
				} else {
					$content = $content.Replace("</configuration>", "    <runtime>
        $magicWords
    </runtime>
</configuration>
")
				}

				# Back up to .bak files
				$backupNumber = ""
				While (Test-Path "$($file.Name).bak$backupNumber") {
					$backupNumber = [int] $backupNumber + 1
				}
				
				Copy-Item $file.Name "$($file.Name).bak$backupNumber"
				Set-Content $file.Name $content
			}
		}
	}
}