Anyone who has this problem,
could you please try to update to the latest avast beta? It should have this issue resolved.
To install the beta, please run the program http://files.avast.com/files/beta/aswbeta.exe and follow the on-screen instructions.
Thanks
Vlk
Had the problem on a couple of machines, but with the beta all seems fine, thanks!
Might go slightly offtopic here, but I think it's partly related: before I found out about this thread I uninstalled avast and used the removal utility, but was unable to install the latest version which I tried to download twice from the download page. It stopped when it tried to move/extract files to <windir>\system32 and <windir>\system32\drivers, by using an install exe from ~2003 I was however able to install and update it to the latest versions + the beta.
Found some avast related, locked, registry keys under HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001|ControlSet002|CurrentControlSet\Enum\Root, don't know if they had anything to do with it, but they weren't removed by the removal utility. I tried removing them by using regedt32, didn't solve the problem with installing the latest avast though.
The machines I had problems on were all running swedish editions of w2k sp4.
Anyways, all seems to be working now, thanks for a great program!