Ok so I want to install windows 7 over my existing install of XP and I was wondering what the best thing to do is? Back up my stuff then just stick the disk in and let it install, or do i want to back up what I want to keep format and delete partition etc then put the disk in when the computer is booting and let do it completely clean? Is there any difference? Like will Windows 7 do all that formatting and stuff by itself when installing or is it more like an upgrade and a lot of it will be kept in tact? I'm not bothered how I do it and I'm leaning towards backing up, formatting and doing it from scratch anyway as I want a nice fresh start - but I just need to know if there is any difference in these approaches? I'm sorry if I'm not being very clear... edit: the version of XP that I've got at the moment is 32bit I'm pretty sure, I want to install 64bit win 7 becaue I've got 4gb of ram, intel i5 750 terabyte of space etc is this ok?