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powershellregistry

Test-Path Registry key works in Windows Terminal but not in my .ps1 script

I am wanting to to test if a registry key exists by using Test-Path:

if((Test-Path -Path 'HKLM:\SOFTWARE\IDTSettings') -eq $true) {
    echo "Registry Key Exists, Ignoring this machine."
    exit
}
else {
...

I manually created this key in the registry and it looks like this: Screenshot of regedit for the key that I manually created.

However, running this script will never exit and instead it will go into the else statement.

To test this I tried Test-Path -Path 'HKLM:\SOFTWARE\IDTSettings' in the Windows Terminal and it responded with the appropriate True.

I am confused why these are different and would love if anyone would be able to help with this.

Many thanks

EDIT:

Weirdly if I run the powershell script from Windows Terminal it will detect the registry key fine but If I try to run it from PowerShell ISE it doesn't work. This does fix my problem as the script works properly when I call it so I will close this question. Thank you all for trying to help :)

Solution

  • As you have confirmed, the problem was that you ran your script from the 32-bit version of the ISE, which sees different, 32-bit-application-specific registry information in the HKEY_LOCAL_MACHINE\SOFTWARE subtree (which, expressed as a PowerShell path, is equivalent to HKLM:\SOFTWARE).

    • If use of the 32-bit ISE was accidental (check if the window title ends in (x86)), simply run the 64-bit version instead (e.g., run powershell_ise from a 64-bit PowerShell or cmd.exe session, which launches C:\WINDOWS\System32\WindowsPowerShell\v1.0\powershell_ise.exe)

    • Otherwise, see below.

    If you really must test the existence of a key in the 64-bit HKEY_LOCAL_MACHINE\SOFTWARE subtree from a 32-bit process, more work is needed; one option is to use reg.exe:

    if ($(reg.exe query 'HKEY_LOCAL_MACHINE\SOFTWARE\IDTSettings' /reg:64 *>$null; -not $LASTEXITCODE)) {
  "Registry key exists, ignoring this machine."
  exit
}
else {
  
  # ...
}

    Note that the inverse solution - accessing a 32-bit key from a 64-bit process would be simpler: the 32-bit data is accessible via the HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node subtree
    (if (Test-Path 'HKLM:\SOFTWARE\Wow6432Node\IDTSettings') { ... })