如何在某些“ if”语句中使用Windows版本标题，以确定要检查的Windows更新？

Question

I'm writing a deplorable script designed to basically eradicate any trace of Windows 10 from Windows 7, 8, and 8.1. Pretty much a script version of this program. The script is almost finished (I think), but it seems that the logic in some of my if statements executes even if the variable isn't true.

Here is the portion in mind, with the line that creates the $Caption variable earlier on in the script added to the top for clarity:

$Caption = (Get-WmiObject win32_operatingsystem).caption

if ($Caption = 'Windows 8.1 Professional') {
  if (Get-Hotfix -id KB3044374) {
    Wusa /uninstall /kb:3044374 /quiet
    Start-Sleep -s 30
    Hide-WUUpdate -KBArticleID KB3044374 -Force
    Start-Sleep -s 20
  }
}

if ($Caption = 'Microsoft Windows 7 Professional') {
  if (Get-Hotfix -id KB2952664) {
    wusa /uninstall /kb:2952664 /quiet
    Start-Sleep -s 30
    Hide-WUUpdate -KBArticleID KB2952664 -Force
    Start-Sleep -s 20
  }
  if (Get-Hotfix -id KB2990214) {
    wusa /uninstall /kb:2990214 /quiet
    Start-Sleep -s 30
    Hide-WUUpdate -KBArticleID KB2990214 -Force
    Start-Sleep -s 20
  }
}

It's not a complete deal breaker, as the code still executes giving simple error messages when the updates intended for another version of Windows aren't found, but I'd like to fix this bug in order to maintain good programming principals.

Answer 1

The Get-Hotfix cmdlet does not return a boolean value. It returns an object containing information if it exists on the target system. If, Else operators expect a boolean (logical 1 or 0) input to work correctly.

What you want to do is use the measure ( Measure-Object ) cmdlet like so:

$m = get-hotfix -id KB3124200 | measure
if ($m.Count -gt 0) { //execute code if hotfix is present // }

This will give you an accurate output to base your If statement on.

EDIT: This line:

If ($Caption = 'Microsoft Windows 7 Professional') {

should be:

If ($Caption -eq 'Microsoft Windows 7 Professional')

This link contains a good resource for PowerShell comparison operators.