I created a Windows Service installer using WiX and included a custom action that called PowerShell to run a script.  Unfortunately, I called the script with the wrong parameters and then the service would not uninstall.  So, I tried a lot of different tricks and finally found a recommendation on the web to run the sc.exe command with the delete parameter.  This was the only solution that worked, so I thought I'd share it here.  I executed:

sc delete "My Service Name"

Note that to execute the same command from PowerShell, you must specify the full path to sc.exe because PowerShell has a default alias for sc assigning it to Set-Content.  I executed it as follows:

C:\Windows\System32\sc.exe delete "My Service Name"

I hope this saves someone else some grief in the future.

Rob