Frozen desktop and tool bar using XP

The other night I did a weekly virus check using AVG software and erased a few items that were in my virus vault. The next morning, my computer would boot up properly but everything freezes once I get to my desktop. My mouse pointer will move around fine but I am not able to get a response from any of the ICONS or the toolbar at the bottom. I was able to get my AVG software to run but it did not find any additional viruses after 2 run throughs. When I hit ctrl-alt-del, I can stop processes from running but then I can't get the box to disapppear from the screen. I do believe the computer is working fine since the computer was able to run my AVG software. I attempted to start my computer in safe mode and after a few attempts was finally able to get it to show my desktop, however, i still could not access my icons or toolbar. I did get access to the safe mode "DOS" screen--but alas I am not savvy with knowing what to type-lol. I put my XP disc in and ran the setup and my desktop still is frozen. I'm kinda sorta at wits end at this point and hope that this is a simple fix. One other note--I saw a bubble near my start button that popped up and said "new programs" but it was frozen also.

I can only assume that I deleted a file I needed when dumping my virus vault or else I have a nasty virus that AVG isn't detecting--:-(

Any help in fixing this would be appreciated--I have visited this site several times for help and found it to be an excellent source for computer help in all aspects of computer usage.