I would recommend this product :-
DarkSpy Anti-Rootkit 1.0.5 Test Version (English)
DarkSpy(Freeware) Anti-Rookit is a powerful tool for rootkit detection. DarkSpy is a multiway-based detection tool . It internally combines many effective detection techniques, including DarkSpy's own handlers and also methods used by other famous tools.
DarkSpy 1.0.5 new features:
Enhanced Process/Driver Module detection.
Fixed some problems working with other security software(Karspersky...etc).
Enhanced process force terminate functionality.
Start to support multi-cpu and hyperthread.
Registry functionality added.
Help document added.
Use it at your own risk.
Please take not that it does not run in Vista..