This is available only in Windows XP:

All of you know that when you open up taskmgr.exe it shows multiple instances of svchost.exe, and you probably wonder what they are. Well here is an easy way to find out:

Since so many critical services are run with each svchost,
You can see which ones are being used by opening a cmd prompt and running:
tasklist /svc /fi "imagename eq svchost.exe"