Macbook Pro Fuzzy Green Screen & Won't Install Mavericks

Hello

I've had my Macbook Pro 15 Inch since late 2011 and recently i've been getting this Green Screen that fuzz's & shows up randomally, so i uninstalled Mavericks and tried to reinstall it ever since i'd been having this problem. It won't reinstall and i need a little bit of help getting it fixed.