Possible problem with AVG

I kept getting messages to update my computer to AVG 2011. I run two machines in my computer repair home business. Well I did so being I've never had any trouble with AVG in the past. Well Sunday morning my roommate was on one of the computers and it ran a scan on it's on. After that was done it had a screen poped up asking to restart the computer which he did. As it was coming up It gave a message that I needed to activate Windows which I thought was strange because the machine had been running with no problems in the last 7 months. So I tried to activate Windows and it crashed the computer losing everything one of my business files on that computer. Thank god I just backed up the other machine the day before because the following day it did the same thing to the second machine but I can still get it up to the desktop. But when I go to add and remove in the control panal it won't uninstall. It keeps asking for a product key for the virus program. Has anyone ran into this problem yet and if you have is there a fix for it? Any help I can get would be a great relief because I have about 50 customers out there with this program on their computer. And I don't feel like reloading that many computers right now being I'm only set up to reload three at a time hard wired and unlimited for the wireless ones being my DSL modem is wireless. It would be after Christmas before I get this all done working 10 and 12 hour days. The money would be good but I would have a lot of unhappy customers because of it.