Cannot uninstall application using Powershell - powershell

Question

I am trying to upgrade an application using an .msp file but every time I run the script I get a message saying the product I'm trying to upgrade from does not exist. My thought was there might be a bug in the original MSI so I decided to uninstall the application and a full install to the new version. When I run the script to Uninstall it works on some machines but not on others. When I try to uninstall using powershell it fails. When I use MSIEXEC /X I get the following message
"This action is only valid for products that are currently installed".
Next I decided to try and repair using MSIEXEC /fa and I get this:
"This installation package cannot be opened. Verify that the package exists and that you can access it, or contat the application vendor to verify tat this is a valid Winds Installer package"
The strange thing is I can uninstall the application with no problems from Add\Remove programs with not issues and install the upgrade. The problem with this is that I have over 3000 users. From SCCM, I tried to supercede the old version to uninstall before installing the new version and that also failed. Any help you guys can provide would be helpful. The application is Taxprep Forms 2021.1.0 upgrading to 2021.2.0. i have added 2 of the scripts I tried.
For this script I tried doing a repair first then uninstall. I also tried using both product code and app name:
Set-ExecutionPolicy -Scope LocalMachine -ExecutionPolicy Bypass
$uninstall32 = gci “HKLM:SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\” | foreach { gp $_.PSPath } | ? { $_ -match “Taxprep Forms 2021” } | select UninstallString
$uninstall64 = gci “HKLM:SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\” | foreach { gp $_.PSPath } | ? { $_ -match “Taxprep Forms 2021” } | select UninstallString
if ($uninstall64) {
$uninstall64 = $uninstall64.UninstallString -Replace “msiexec.exe”,”” -Replace “/I”,”” -Replace “/X”,””
$uninstall64 = $uninstall64.Trim()
Write "Repairing Old install..."
Start-Process "msiexec.exe" -arg "/fa $uninstall64" -Wait
Write “Uninstalling…”
start-process “msiexec.exe” -arg “/X$uninstall64 /qb” -Wait}
if ($uninstall32) {
$uninstall32 = $uninstall32.UninstallString -Replace “msiexec.exe”,”” -Replace “/I”,”” -Replace “/X”,””
$uninstall32 = $uninstall32.Trim()
Write "Repairing Old install..."
Start-Process "msiexec.exe" -arg "/fa $uninstall32" -Wait
Write “Uninstalling…”
start-process “msiexec.exe” -arg “/X$uninstall32 /qb” -Wait}
I also tried:
Set-ExecutionPolicy -Scope LocalMachine -ExecutionPolicy Bypass -Force
$DisplayName = "Taxprep Forms 2021"
$TaxprepCheck = (Get-ItemProperty HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\* | Where { $_.DisplayName -eq $DisplayName}) -ne $null
$PublicUser = "C:\Users\Public\CCH\Taxprep Forms 2021\"
$UnInstallCheck = "C:\Users\Public\CCH\Taxprep Forms 2021\Forms2021Uninstall.txt"
$Uninstalled = "C:\Logs\TaxprepForms2021.1.0Uninstalled.txt"
$TaxprepVer = Get-WmiObject -Class Win32_Product | Where-Object{$_.Name -eq $DisplayName}
If(-Not $TaxprepCheck)
{
New-Item $Uninstalled -Force -ErrorAction Stop
Set-Content $Uninstalled "Taxprep Forms 2021.1.0 is not installed"
}
else
{
$TaxprepVer.Uninstall()
New-Item $Uninstalled -Force -ErrorAction Stop
Set-Content $Uninstalled "Taxprep Forms 2021.1.0 is successfully Uninstalled"
}
If (Test-Path -Path $PublicUser)
{
New-Item $UnInstallCheck -Force -ErrorAction Stop
Set-Content $UnInstallCheck "Taxprep Forms 2021.1.0 Uninstalled"
}
Else
{
New-Item -ItemType "directory" -Path $PublicUser
New-Item $UnInstallCheck -Force -ErrorAction Stop
Set-Content $UnInstallCheck "Taxprep Forms 2021.1.0 Uninstalled"
}
I have verified that the application is installed. It's in the registry. These scripts work on some computer and not on others. The machines it doesnt work on I have to uninstall the application through add\remove.

Answer 1

Ok so it seemed I may have caused my own issue. When I initially deployed the application in SCCM, I set the User experience to “Install as User”. The switch I used when calling msiexec was All Users = 2. I switched the install to “Install for System and set All Users = “”. I would need to deploy the msi and do a full install rather than an upgrade using the msp. Installing as User may have messed up the registry setting for the initial install.