Try downloading ccleaner click here stick to the windows tab and clear all that it finds. Disable system restore this will clear out all restore points but nasties can hide in there.
Rerun your scans but let them reboot in between scans it may be worth running them in safe mode. Have you tried a2 click here also run a scan with your anti virus apps as well.
If after you have run all the normal scans the problem still persists you will need to download hijack this and post a logfile to click here