Unwanted reboot after installation of Avast

I need a new driver or something to replace a driver Avast version 4.6 Home Edition installed, that caused my computer to reboot in the middle of a program I was working on. Any ideas of what happened? My operating system is XP Professional SR2. Please email me replies at dnsworld@msn.com.

Thanks, Always my best and have an awesome day,

Don

Do you have any (recent) files in C:\Windows\Minidump folder?