I'm trying to install Powershell 2.0 and it's telling me I need to uninstall an earlier version? It's not in the installed app list and there's no obvious uninstall in the windowspowershell\v1.0 directory under system32.
You have to have Show Updates checked in Add/Remove Programs to see Powershell.
Remove it as any other windows update as stated, unless you've done a service pack. Because PS is installed as an update, service packing removes the uninstall cache. Honestly, it's easier to roll back the SP, remove the PS update, and re-service pack the thing. So either upgrade to vista or don't make any plans ;)
How to uninstall Windows PowerShell 1.0 To uninstall Windows PowerShell 1.0, follow the steps that are appropriate to your operating system. Windows Vista Click Start, type appwiz.cpl in the Start Search box, and then press ENTER. In the list of tasks, click View Installed Updates. In the Uninstall an update list, right-click Windows PowerShell(TM) 1.0 (KB928439), and then click Uninstall. Follow the instructions to uninstall Windows PowerShell 1.0.
Note If you disable Windows PowerShell by using the Turn Windows Features on or off option, this does not satisfy the Compatibility Check process. You must uninstall Windows PowerShell. Windows Server 2003 Click Start, click Run, type appwiz.cpl, and then click OK. Click to select the Show updates check box. In the Currently installed programs and updates list, find the entry for the hotfix that installed Windows PowerShell 1.0. Depending on the installation package that was used, this entry resembles one of the following: Hotfix for Windows Server 2003 (KB926139) Hotfix for Windows Server 2003 (KB926140) Hotfix for Windows Server 2003 (KB926141) Click the Windows PowerShell hotfix entry, and then click Remove. Follow the instructions to uninstall the hotfix for Windows PowerShell 1.0. Note By default, if Windows Server 2003 Service Pack 2 is installed on the system, PowerShell 1.0 cannot be uninstalled. To resolve this issue, follow these steps: Follow the steps in the following Microsoft Knowledge Base (KB) article, 931941, to trust Windows PowerShell 1.0 that was introduced in KB926139: 931941 (http://support.microsoft.com/kb/931941/ ) The Oobmig.exe tool is available to restore trust to out-of-band updates after you install Windows Server 2003 Service Pack 2 Note You may have to restart the computer. Check whether the update can be uninstalled by using Control Panel. If the update cannot be uninstalled in this manner, uninstall PowerShell manually from the following location: C:\WINNT\$NtUninstallKB926139$\spuninst\spuninst.exe Note You may have to restart the computer. Windows XP Click Start, click Run, type appwiz.cpl, and then click OK. Click to select the Show updates check box. In the Currently installed programs and updates list, click Windows PowerShell(TM) 1.0, and then click Remove. Follow the instructions to uninstall Windows PowerShell 1.0.