Which PC for £500

unless you're particularly into PC video games or have a windows/apple programme you use a lot, get something without an installed OS then get Linux.. It's free, constantly updated and can do pretty much everything you'll need without much fuss.

in my eperience Linux is a good OS but needs a hands on approach and a link to the Linux forum for help, which is often. So many niggles that are non existent in Win7.