Script fails to run RRS feed

  • Question

  • $app = Get-WmiObject -Class Win32_Product | Where-Object {
      $_.Name -match "7-zip"

    $app = Get-WmiObject -Class Win32_Product | Where-Object {
    $_.Name -match "7-Zip 9.20 (x64 edition)"

    Used this script to delete 7zip from  client computer and found no issues. But when I try to run it again got the error:

    You cannot call a method on a null-valued expression.
    At C:\Scripts\7zip.ps1:2 char:1
    + $app.Uninstall()
    + ~~~~~~~~~~~~~~~~
        + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
        + FullyQualifiedErrorId : InvokeMethodOnNull

    Monday, February 24, 2020 10:35 PM

All replies

  • If the installation of the app is not there anymore the command fails. Did you check if 7zip is still installed?

    And please format your code as code: How to Use the Code Feature in a TechNet Forum Post When you post error messages or example data you shoud format them as code as well, please.

    Live long and prosper!


    • Edited by BOfH-666 Monday, February 24, 2020 10:44 PM
    Monday, February 24, 2020 10:42 PM
  • 7Zip is not an installed app.  It is an XCOPY app that is xcopied into its folders and separetly items are registeres.

    To detect 7Zip just look for it:

    Get-Item 'C:\Program Files\7-zip\7z.exe'

    If it is on your system this will find it except if you have moved it or changed the install folder.


    Monday, February 24, 2020 10:48 PM
  • To uninstall 7-Zip do teh following.

    Start-Process 'C:\Program Files\7-zip\Uninstall.exe'


    Monday, February 24, 2020 10:49 PM
  • I just noticed that there are MSI versions of this program.  They should be removable in your way but the code cannot be run twice in a row.


    Monday, February 24, 2020 10:52 PM