I was tasked with upgrading a 2003 Windows Server to 2008 over the weekend recently and ran into a few minor issues trying to get the upgrade started. The main one was that the Server 2008 installer would not continue past the compatibility check as long as Windows PowerShell 1.0 was installed. PowerShell 1.0 was released as a hotfix prior to server 2003 SP2 and was included in the SP2 package. When I went into Add/Remove Programs, I didn’t see the PowerShell update in the list. Even after removing SP2, PowerShell was still present on the server and would not allow the Server 2008 upgrade to even start. [more]
I wanted to try manually uninstalling the hotfix from the $NtUninstallKBXXXXXX$ folders located in C:\Windows, but the folder that housed the PowerShell 1.0 hotfix info was nowhere to be found. Most likely, someone had removed those folders to clean up disk space or they were removed with the installation of SP2. In either case, I was stuck.
Fortunately, we had another Server 2003 32bit machine running out on the network that still had the $NtUninstallKBXXXXXX$ folder that I needed. I copied it over to this original box and tried the uninstaller. It successfully uninstalled PowerShell without any extra registration on my part! After this was removed, the upgrade to Server 2008 ran smoothly.