CODEWITHSUNDEEP
powershellinvoke-command
spickles
spickles

Reputation: 645

Invoke-Expression Not Running Command

I am pulling in a text file that was previously created that simply lists the KB numbers for all currently installed Windows Updates. I am trying to pull this file in and call wusa.exe and pass it the KB number to perform an uninstallation.

$a = Get-Content c:\hotfixid.txt
foreach ($kb in $a) {
    $command = 'cmd /c wusa.exe /uninstall /kb:' + $kb.Trim().Substring(2) + ' /quiet /norestart'
    #Write-Host $command
    Write-Host "Currently uninstalling $kb"
    Invoke-Expression -Command:$command
}

If I use

Write-Host $command

and copy that directly to a run dialog box in Windows, it completes successfully.

What happens when I run it in a PowerShell script is that it only outputs the Write-Host portions one after the other in about 2 seconds. I do not see any command windows opening and I don't see it actually DOING anything. I am running the PowerShell script 'As Administrator' with an unrestricted execution policy. I have also tried adding 'runas' to the $command to call the CMD window each time with administrative privileges and it made no difference. Calling it via Invoke-Command as well makes no difference.

Upvotes: 0

Views: 3230

Answers (1)

Jason Shirk
Jason Shirk

Reputation: 8019

PowerShell can run most commands directly w/o too much trouble.

Using Invoke-Expression just complicates matters, as does Invoke-Command or Start-Process, because you need to get the quoting right, and pass the arguments in a slightly unnatural way.

You can even skip running cmd.exe most of the time.

Try the following:

wusa.exe /uninstall "/kb:$($kb.Trim().Substring(2))" /quiet /norestart

Upvotes: 1

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