Hello, I have a quite popular problem with trojan horse on my PC, which is downloaded each time, when I kicked it out. ;)
I have: avast! Home Edition, Malvarebytes Anti-Malvare and Comodo Firewall activated and regular updated.
All of these are signalise that is a problem with two separated files (wuaudit.exe - reported by avast! and dwm.exe - reported by MBAM & Comodo).