every time i try to do a boot time scan it gets to the point where it is going to scan but a error message comes up for a split second and then the system reboots.the error message comes up to fast to see.i have uninstalled and reinstall but the same thing keeps on happening.eny help would be appreciated
Hello. No fear. 
Most of us are having this problem, it is a temporary bug, in that it shall be rectified next program update. Otherwise, avast! is in fine order and you can proceed with scanning as normal.
See this thread for more info: http://forum.avast.com/index.php?board=2;action=display;threadid=3675
(be sure to view all three pages of the thread for responses from the fix team.) Cheers!
hi chameleon.thanks for the reply i just read the other post.i just reinstalled avast i had this problem about a month ago and i uninstall avast and tonight i reinstalled avast thinking that it would work rite iam glad i read the other post i was going to uninstll it again…