How can I call a command using the following output? - powershell

Question

Please see the following command I'm running to obtain the GUID of a particular application. It works as expected as you can see from the screenshot underneath.
Get-ChildItem -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall, HKLM:\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall |
Get-ItemProperty |
Where-Object { $_.DisplayName -match "Dell SupportAssist" } |
Select-Object -Property DisplayName, UninstallString
What I'd like to do is call the uninstall command from the output GUID. So something like:
MsiExec.exe /X{OUTPUT}
or for this example
MsiExec.exe /X{95BD6E30-2B18-4FB0-B5AE-8250E5584831}
Can this be done?
I don't want to use a huge VBS script that I can't read that you found online, I'd like to understand it bit by bit ;)
I don't want to use Get-WmiObject Win32_Product - See https://gregramsey.net/2012/02/20/win32_product-is-evil/.

Answer 1

Your registry query returns a custom object with the uninstall command string as one of its properties. To invoke that command string you can create a scriptblock from that string and then invoke that scriptblock (e.g. via the call operator). Pipe the output of your PowerShell statements into a ForEach-Object loop like this:
... | ForEach-Object {
& ([Scriptblock]::Create($_.UninstallString))
}

Answer 2

You may try as #Ansgar mentioned something like:
Code edited with example for Dell Power*:
$DellSoftware = Get-ChildItem -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall, HKLM:\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall |
Get-ItemProperty |
Where-Object { $_.DisplayName -like "dell power*" } |
Select-Object -Property DisplayName, UninstallString
$DellSoftware.UninstallString -match '(?<MSI>\w+.exe) (?<Args>\S+)'
Start-Process -FilePath $Matches.MSI -ArgumentList $Matches.Args
If you check the $Matches variable it should contain:
Name Value
---- -----
Args /X{18469ED8-8C36-4CF7-BD43-0FC9B1931AF8}
MSI MsiExec.exe
0 MsiExec.exe /X{18469ED8-8C36-4CF7-BD43-0FC9B1931AF8}
It returns a hash table with the grouped matches. This is why I am being able to separate the executable into the MSI key and the arguments into the args key. Then starting the process calling the executable as a FilePath param and providing the args for the ArgumentList param.
Then the result:
What is happeinig here is that the property UninstallString, returns, as you may guess - String. You need to tell to the PowerShell to treat this string as an expression.
To do so you need to use the & symbol in front, putting the statement, that you would like to execute in round brackets.
Same behaviour could be observed, when you try to launch a file from a location that contains white space. Because of it, powershell puts it in brackets, and to be able to execute it, puts the & in front - i.e. & 'C:\Program Files\'
Hope that clarifies the case :)

Answer 3

If it's an msi, it's very easy with the package commands:
get-package *dell* | Uninstall-Package -whatif
EDIT:
If you want the exact command... (-force in case it asks to install nuget)
Uninstall-Package 'Dell SupportAssist' -Force

Answer 4

Guys my colleague found this on another Stackoverflow post:
$uninstall32 = gci "HKLM:\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall" | foreach { gp $_.PSPath } | ? { $_ -match "Dell SupportAssist" } | select UninstallString
$uninstall64 = gci "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall" | foreach { gp $_.PSPath } | ? { $_ -match "Dell SupportAssist" } | select UninstallString
if ($uninstall64) {
$uninstall64 = $uninstall64.UninstallString -Replace "msiexec.exe","" -Replace "/I","" -Replace "/X",""
$uninstall64 = $uninstall64.Trim()
Write "Uninstalling..."
start-process "msiexec.exe" -arg "/X $uninstall64 /quiet" -Wait
}
if ($uninstall32) {
$uninstall32 = $uninstall32.UninstallString -Replace "msiexec.exe","" -Replace "/I","" -Replace "/X",""
$uninstall32 = $uninstall32.Trim()
Write "Uninstalling..."
start-process "msiexec.exe" -arg "/X $uninstall32 /quiet" -Wait
}
This works perfectly and includes switches for silent uninstall - It doesn't seem to use Win32_Product.
Any reason why this wouldn't be appropriate rolling out en masse compared to the suggestions above?