Have you done an AV scan? It's probably a good idea, just in case. Scans for spy/adware also wouldn't hurt.

Was the program one that you'd downloaded using p2p?

You could try deleting in safe mode. Or use the computer's search to look for all files & folders associated with the program, then delete everything that way. If files are stubborn, you might need some tools to help remove them. Check out this thread for more info. I've used both Unlocker & DelinvFile & they work well.
http://www.gnutellaforums.com/showpo...35&postcount=2