Well, chances are, you're trying to uninstall a windows service. This error tends to happen when you don't stop the service before attempting to uninstall it or/and some associated process or handle hangs around, preventing the service from being uninstalled. One common culprit is services.msc - it's particularly bad because if you've stopped the service before running your uninstaller, you probably still have the services.msc window open. Before you go restarting the machine etc, MAKE SURE YOU CLOSE SERVICES.MSC, in your session and any other active rdp session. If you close and reopen the console, you'll probably find that your service has now been successfully deleted. Solved with zero efforts, yippee :)
