Use services.msc or (Start > Control Panel > Administrative Tools > Services) to find the service in question. Double-click to see the service name and the path to the executable.
Check the exe version information for a clue as to the owner of the service, and use Add/Remove programs to do a clean uninstall if possible.
Failing that, from the command prompt:
sc stop servicexyz
sc delete servicexyz
No restart should be required.