Bonjour is an Apple networking utility that often gets installed with itunes and even adobe products.
If aford10's revo uninstaller doesn't do the trick then try these manual removal steps:
1. Go to Start->Run and type CMD and press the Enter Key. Type the following command:
"C:\Program Files\Bonjour\mDNSResponder.exe -remove"
2. Navigate to the following folder: C:\Program Files\Bonjour
3. Rename the mdnsNSP.dll file in that folder to mdnsNSP.old
4. Restart your computer
5. Delete the the C:\Program Files\Bonjour folder