elevated.ps1

function elevated {
<#
.SYNOPSIS
    Runs a scriptblock in an elevated shell
.DESCRIPTION
    A given script block is executed in a an elevated powershell, if the current host isn't elevated.
    The elevated shell location is moved to the current directory. A profiole isn't loaded for the 
    elevated shell because of performance reasons.
    The output of the shell is captured and exported as CLI-Xml to a temorary file and imported by the 
    original shell after the the elevated process ended.
.EXAMPLE 
    Runs a elevated explorer in current directory
    elevated { ii . }
.LINK 
    Based on http://blogs.msdn.com/b/virtual_pc_guy/archive/2010/09/23/a-self-elevating-powershell-script.aspx
#>
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true,Position=0)]
        [scriptblock]$ContinueWith
    )
    process {

        $myWindowsPrincipal=New-Object System.Security.Principal.WindowsPrincipal([System.Security.Principal.WindowsIdentity]::GetCurrent())

        if ($myWindowsPrincipal.IsInRole([System.Security.Principal.WindowsBuiltInRole]::Administrator)) {
            # this is an admin process. do ot elevate
            Write-Verbose "Host is already elevated..."
            $ContinueWith.InvokeReturnAsIs()
        } else {
            # Start scriptblock in elevated process
            Write-Verbose "Host isn't elevated yet. Starting elevated process."
            
            # Start script block execution at current location. All generated obejcts are exported to temporary file
            $tempFileName = [System.IO.Path]::GetTempFileName();  
            $commandString = "Push-Location {0}; {{ {1} }}.InvokeReturnAsIs() | Export-Clixml -Path {2}; Pop-Location" -f $PWD,$ContinueWith.ToString(),$tempFileName
            
            Write-Verbose "Executing script block in $PWD and storing results temporarily in $tempFileName"
            
            Start-Process "powershell" `
                -ArgumentList @("-noprofile","-Command",$commandString) `
                -Verb runas `
                -WindowStyle Hidden `
                -Wait 
                # has no effect: # -WorkingDirectory $PWD

            # Now read temorary file and show them in shell
            Write-Verbose "Importing results from $tempFileName"
            
            if(Test-Path $tempFileName) {
                if((Get-Item $tempFileName).Length -gt 0) {
                    # read output from eleveted shell as powershell objects
                    Import-Clixml -Path $tempFileName -ErrorAction SilentlyContinue
                }
                # clean up existing temp file
                Remove-Item $tempFileName | Out-Null
            }
        }
    }
}