I've already done that, and is the same. Also i have downloaded a 40 mb setup file for avast 5 pro, and the one that is in the offiial page is about 39 mb, why is the difference? the one of 40 mb, is for the upgrade from 4.8, but it also freezes my pc, as the 38 mb setup. I cant install 5 pro from 4.8. And alone as a fresh install it's the same. A MESS. I have win 7 64 bits, 8 gig of ram, and a 500 gb hdd and a quad core processor. The only version i can install on my pc, is the free edition. And it works awesome. But is a shame i can't upgrade to 5 pro my 4.8 pro.
I have tried everything i read it works for others but in my pc, is always the same result. Avast 5 pro freeze my pc.