Anton,
Lets do the easy things first shall we.
Shut down all other spyware, and adblocker software.
You CAN'T have any other resident antivirus on your system with Avast. If you do, you will need to shut down that resident scanner.
Rerun Avast full scan. If it completes, then one of the anti-?? programs is interferring and you can flip them back on one at a time to see which one.
If it does not complete the scan, then let me know if you are familiar with using MSCONFIG utility.
Also let me know:
What OS do you have?
Which Avast (Home or Pro), and version?
Which build of Avast is now installed?
Have you ever had NORTON installed? (very important!)
A solution to your problem should not be too hard to find.
techie
Edited: Read your last post. Our posts crossed. Since your entire system freezes, we may have to look into available system resources as well. This is remote, but we will check it later on anyway.
What is your Ram available?.
Thanks