Rac's prog might help but you can view all start up programmes by typing msconfig in the run prompt and click on the startup tab. This will show you all the item that will load on windows start. Check these for any thing suspicious also note the registry key for it's location (if you can - it's a bit of pain as by default the window is not resizable) and untick it. Also check the Services tab as well, there will be a load in there but again check for anything odd.
Next do a search for the item on your PC and delete it also take a note of the name of the folder it is in (if there is any)
Then go into the registry (type regedit at the run prompt) and go to the registry location noted in step one. Also to a search for the item as it will be in other places as well. The most likely places will be in:
HKEY_CURRENT_USER\Software
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
and the same keys in HKEY_LOCAL_MACHINE
BE CAREFULL - don't delete the entire key just the entry in the key - if your a little unsure do a back up of the registry (file > export)