I would check out the following

O2 - BHO: ohb - {8037F7F0-80B6-453A-A7CB-5371A4A09BB8} - C:\WINDOWS\system32\nsk16.dll
O4 - HKCU\..\Run: [Closed Service Drivers] kiotper.exe
O4 - HKCU\..\RunServices: [Closed Service Drivers] kiotper.exe
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL

Not to say this is your problem, but I personally haven't seen those items before. Googling kiotper.exe gives you nothing which leads me to think it might be something company based.