Disable system restore, reboot, fix the following things with HJT, reboot. Than run a full system scan with Avast.

\WINDOWS\System32\wuamgrd.exe
04 - HKLM..\Run: [spoolsv.exe] wuamgrd.exe
O4 - HKLM..\Run: [ATI VIDEO REGKEY] ati2vid.exe
04 - HKLM..\RunServices: [Windows Service Pack2] svchhost.exe
O4 - HKLM..\RunServices: [spoolsv.exe] wuamgrd.exe
O4 - HKLM..\RunServices: [ATI VIDEO REGKEY] ati2vid.exe
O4 - HKCU..\Run: [ATI VIDEO REGKEY] ati2vid.exe
O4 - HKCU..\Run: [spoolsv.exe] wuamgrd.exe