Normally, when you uninstall an application it should remove all associated services automatically. Unfortunately, in practice this not always works.

For example, after removing McAfee antivirus you may end up with couple of leftover services that do absolutely nothing.

Such services can be removed manually from the command prompt.

• First of all open command prompt and run sc getkeyname “<Service Name>“
  Where “<Service Name>” is name of the service as it appears in services.msc console
  This will return service KeyName which you will need in the next step
  
  
• Now run command sc delete “<KeyName>”
  Where “<KeyName>” is the name you found in previous step
  You will get a confirmation that service was successfully removed
  
  

If, running sc delete “<KeyName>” you get error: OpenService FAILED 5: Access is denied, check this article.

Windows XP
Windows Server 2003