If you are trying to find out if a virus has created a windows service, this is what you need to do. Open the system configuration utility by Clicking on Start > run (in XP) and typing msconfig in the box (in Vista, the box is already open) . Click on the Services tab after the system configuration utility window opens.

Check in the box that says "Hide all microsoft services", that will help you to find the virus created service easily. Now read the list of services, and if you know the name of the service, that the virus has created, then uncheck the box in front of it's name. Then press Apply, Press Close/Ok. It will prompt you to restart the computer. You can restart immediately or later. After restart the service will be disabled, and it will help you when you are deleting the file of the virus from the hard disk. Remember, if the service is still running, windows will prevent you from deleting it's file from the hard disk, that is why you need to disable it from the services list.