I’m not sure if what happened coincided with the security update of IE7 or not but here goes.
I started having freezing problems when I ran IE and visited websites (about every 10 -15 min). I did a total scan for malware using various methods. I made sure that there were no processes running that would conflict with Avast!
So, I’m looking around at what it might be, and found something interesting that worked. I went to Tools/options/advanced and saw the phishing filter. I disabled it figuring that Avast! already performs that function. I have tried it now for two days and not a single freeze. It appears that what I did worked.
Oh and btw, today I had someone suggest a site and I went there and the “nuke” symbol came up. NICE!
Besides checking the firewall, maybe you could follow general procedures to make sure your computer is clean:
Clean your temporary files.
Schedule a boot time scanning with avast with archive scanning turned on. If avast does not detect it, you can try DrWeb CureIT! instead.
Use SUPERantispyware, MBAM or Spyware Terminator to scan for spywares and trojans. If any infection is detected, better and safer is send the file to Quarantine than to simple delete them.