Does the problem persist even if you restart the computer...?
I just rebooted and performed another bootscan. This time everything was ok and there were no error codes. At first I thought it may have been a trial install of NOD32 or Kaspersky as a 2nd option to Avast. (I've uninstalled both). Many industry writers recommend having a 2nd AV program. Unfortunately those two don't work well in tandem with another program (even when they're not memory resident).
My conclusion is that after my most recent Avast program upgrade, instead of doing a bootscan after a 2nd re-boot, I performed the bootscan before Windows 2000 pro fully reloaded again after the upgrade. Hopefully, that was the reason for the Error 42100 all over the place.
I have several questions about the bootscan.
1) Does this only scan the hard drives?
2)Can it be set up to scan the registry?
3) How do you set up a bootscan from the normal user interface? I can't seem to find the option. I always have to switch to the simple user interface.
4) Shouldn't the pagefile.sys file be scanned on occasion?