One of my laptops was running avast! 4.8 Free and ZoneAlarm. The current key was about to expire and I decided to upgraded to avast! 5.0 Pro. I uninstalled ZoneAlarm (rebooted) and avast 4.8 Free (rebooted). The avast! 5 Pro install appeared to work (no reboot required). All subsequent reboots would hang with partial display of desktop icons. The Start bar was unresponsive. The Task Manager showed no unusual CPU activity. The harddrive light showed low levels of activity. After waiting about 15 minutes, I shutdown the system using Ctl+Alt+Del. Windows reported that explorer.exe was not responding - I manually terminated the task.
I repeated the boot process several times, all with the same result, all pointing to a problem with Windows explorer.exe. I was able to boot into Safe mode and uninstall avast! 5.0 Pro. A re-install again seemed to work but I had the same hang on a reboot. This time, even Safe mode showed the same hung explorer.exe symptoms.
I was able to recover via System Restore and am now back on avast! 4.8 Free.
In scanning the forums for related issues, suggestions include:
- disabling behaviour shield
- using the avast! uninstall utility to remove all traces of avast! 5.0 and 4.8, then install avast! 5 again
- follow previous step, install avast! 4.8 and then install avast! 5 on top of 4.8
- not trying to install avast! 5 on Win XP/SP3 at all
However, I did not find a post that matched my symptoms. Any suggestions?
Thanks, Norbert