With MSSE/Defender, ClamWin, Avast, AVG, Avira etc., all offering free active AV, and free 2nd opinion scanner and/or cleaners avail from Zillya, AdwCleaner, Junkware Removal Tool, BitDefender, Comodo, Dr. Web, ESET, F-Secure, HitmanPro (free to scan, 30 day temp license to disinfect), Kaspersky, MalwareBytes, SmadAV, EmsiSoft, Tiranium, TrendMicro.....
Well, why pay at all?