Did you run a boot scan with Avast? If not do.
I also use PC Tools Spyware Doctor. Best on the market.
If Avast boot scan doesn't help try the others in Safe Mode.
MOST IMPORTANT. Make sure their not False Positives.
Last resort before reformat. Pull the drive and put it in a USB caddy and hook it to your computer and scan the external drive. In this way Windows is not running on that drive and you'll catch it while it's sleeping.


John
ESI Gigaport HD+
Lenovo Turion II /4 Gig Ram/ Win7x64 be
15.6" Monitor
"The only Band is a Real Band"
www.wintertexaninfo.com/BANDS/JohnnyD.php