Re: The uninstall tool...A lot of AV's leave stuff behind that the built in uninstaller sometimes does not remove, (including Norton, AVG, McAfee, and others.)
Hence the use of an uninstall tool. (Avast has one too, for difficult uninstalls.)
Re: Program changes detected...Do you use the Secunia PSI? I have no idea why the use of an AVG remover should have also removed the programs you list. Can you still view PowerPoint files? Might need to reinstall that one of you can't.
The Flash uninstaller is probably no big deal, you can get that easily enough if needed, but as to why they are removed, it's a mystery.
Re: The device is not ready errors..this has me flummoxed. Is the external drive plugged in and on?
Re: Archive is password-protected.. this is not unusual, and doesn't matter. (Try searching the forum for this sort of message in scan results.)
In summary, I don't really know what to do, either.
What I would try is downloading a fresh copy of Avast from the Avast website, download the
Avast uninstall utility, go offline, and do a full uninstall/removal/re-install from scratch. Uninstall requires you to disable the self defense module (right click the tray icon, select "settings">"troubleshooting" and tick the appropriate box.)
Reboot whenever prompted in this process, and run the uninstaller before installing again.
Run the uninstaller and then the installer file "as administrator", and "OK" your way through any UAC prompts.
(I have quite limited experience of Vista, but elements of it are a bit of a pain, to my mind.)
See how that goes.