Hi there
First of all,I love Avast!
I've been using Avast for more than 2 years
But now I use windows 8(64 bit) and when I install Avast,after first restart,i can't use my PC
I type in my PIN(windows

and please wait sign stays unusually long,then black screen...I can't see start screen,I can't see desktop...I just launch task manager,open explorer from there and uninstall avast.Then everything is OK
Additional details:
I tried both avast 7 and avast 8,no luck
I don't have any issues with other antiviruses(My keyboard's media control keys doesn't work when I use AVG)
i5,windows8-64bit...can provide any other information
Thanks in advance