Windows XP is braking after Avast 4.8 update

[etalk]

I use Avast Pro 4.8 on some PC with Windose XP SP3. Last Thursday, September, 23, at one computer after Avast update, Windows became a very, very slow. In the task manager there was no active process running, hard disk uttered rhythmic sounds. After 10-15 seconds after the restart the computer in normal mode situation recur. But the computer has successfully booted in safe mode. I had uninstalled Avast (in safe mode), the problem disappeared. After that I re-install Avast and new problems do not arise.
Today I turned on another computer (it was a long time off), there was an Avast update too and repeated the problem - a very, very slow work Windows, nothing can be done. Solved the problem by Avast reinstalling.
Anybody else experiencing this problem?

[DavidR]

After what avast update, virus signatures or program (if program what version number, e.g. 4.8.1368) ?

Avast5 has been out now for over 8 months now. So my suggestion would be for you to update to avast 5. This can't be done through the normal avast 4.8 update process as avast5 is so different it requires that you download the full installation file.

[etalk]

After what avast update, virus signatures or program (if program what version number, e.g. 4.8.1368) ?

Avast5 has been out now for over 8 months now. So my suggestion would be for you to update to avast 5. This can't be done through the normal avast 4.8 update process as avast5 is so different it requires that you download the full installation file.

Unfortunately, I do not know what was updated. I do automatically update daily. The problem first arose on September, 23.
Yes, I have already upgraded to avast 5 for one computer. At the other PC avast 4 works after re-installation. In the third avast 4 runs without any problems (also updated every day automatically.)

[DavidR]

Well program updates are set (by default) to ask, virus database updates are set to be automatic, but that shouldn't have that kind of impact (XP breaking) as essentially the virus database update doesn't change any XP program files or settings.

With that kind of inconsistency on the systems that are or have run avast 4.8 where there is no problem or in the case of a reinstall of avast 4.8 that wouldn't repair any XP issues. So I can only conclude an unrelated hiccup, but for it to happen at roughly the same time on two, is somewhat strange.

I would suggest you update to avast 5 on those other 4.8 systems also.