"Cannot access the specified device, path, or file" Windows XP

It does sound like the programs you are trying to access are not physically present.Right click on one of the desktop items, click on property. There should now be the property window open up. check on >shortcut>target> in there you should see where the file is actually located. Make sure that you have a drive letter that is physically there. You may have a computer that was either network connected or had external drives with the program files. XP will give you that particular message anytime it can not find the files, it does not sound like your virus program is locking down your drive. you would definitely get a different error message.

If you believe AVG is the cause of the problem you can boot into safe mode. From safe mode you should be able to disable or uninstall AVG. To get to safe mode most computer require you to tap the F5 or F8 key. Your problem also sounds like you computer could be infected with a virus or malware. You may want to boot into safe mode and run a virus and malware scan to see if that corrects the problem.