How to uninstall a Windows service

Method 1 - You can use the SC tool (Sc.exe) included in the Resource Kit.
Open a Command Prompt and enter

sc delete <service-name>

Method 2 - Download and use delserv command line utility. This is a legacy tool developed for Windows 2000. In current Window XP boxes this was superseded by sc described in method 1.

delserv delete <service-name>

Method 3 - manually delete registry entries
Windows services are registered under the following registry key.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services

Search for the sub-key with the service name under referred key and delete it.