Hey http://free.grisoft.com/doc/avg-anti-virus-free/lng/us/tpl/v5 go to that link, scroll all the way down and you will see the download link. This link is from AVG's site and you "WILL" be able to install it without any hassle
I don't know man, I never usually have problems installing applications. I keep clicking Next, but at the end of it I keep getting Failed Installation.