My wifes computer started with pop up ads and 'conduit' infecting her browser. This progressed to running very slow. I did try to download combofix (I know... don't do that) and every time it landed on the computer the computer deleted it instantly. I downloaded on my computer and moved it over with a USB drive and it deleted it off the thumb drive! I ran SuperAntiSpyware and Adwcleaner and when it restarted it hung. All attempts at reboot ended up hanging with a blank screen, even in safe mode. I managed to do a restore back to a previous date, boot in safe mode, and run combofix. I then ran RKill, TDSSkiller and Adw again. I have the logs saved.
It APPEARS to be gone now but I think with as bad as it was I might like a pro's opinion on that.