Same thing just happened to me...
I installed Avast onto a Dell computer that I've been using since my 1year old kicked in my Acer laptop screen. Once I registered it and let Windows install updates, Avast runs for for a minute or so and then locks up my computer. I tried doing a system restore, uninstalling Avast, etc but it locks up before ANYTHING can finish. I'll try starting in Safe Mode for an uninstall and see if that works, but are there any other suggestions.
FYI - this computer worked FINE before I installed Avast, so it's more than a coincidence. I also run Avast on another computer, which uses Vista and have no problems. The Dell has XP...
