What is it?
Adware.Binet File names: Varies: Bi.dll and Biprep.exe; Belt.exe; Belt.ini; Belt.inf; Susp.exe; Susp.ini; Susp.inf

What does it do?
Adware.Binet is a Browser Helper Object that displays advertisements and downloads and installs files. Being a Browser Helper object this kind of thing is VERY easy to get installed on your system. If you have this then please upgrade your system to Windows XP with SP2 to help you avoid this kind of thing.

Removal:
Symantec has the full dirt ( Here )