Have you tried starting your computer in safe mode to do the scans, and to see if the problem is there as well?
There are a couple of ways to get into safe mode:
1: restart your computer.after the bios POST screen tap F8 and select safe mode from the list
2: Click start--->run--->type msconfig and click OK or press enter and the system configuration window opens. Click the BOOT.ini tab and tick the box beside safeboot then click ok. You will be asked to restart your computer. Click restart and your computer will start in safe mode.
If you do option 2, after you are finished with safe mode Click start--->run--->type msconfig and click OK or press enter and the system configuration window opens. On the General tab put the dot in normal startup and click ok..you will be prompted to restart your computer..click restart and your computer will start normally.
Please let us know if this resolves your issue...