OK, technically you can't upgrade from XP to Windows 7. But that is what the nice guys at Language Log call nerdview
. You can't click a button in the install process that has Upgrade on it and come back later to find that you are now running Windows 7. But you can follow a series of steps that takes you from your current XP installation full of applications and pictures and mailbox and IE favourites and desktop wallpaper and all that jazz, and end up with a Windows 7 installation full of all the same stuff. Well, not your applications, but all your data and your settings. That feels like an upgrade to most people, and if the applications they use are free (Messenger and other downloadable clients) or they have the installation materials and they only use 3 or 4 apps (say, Office) then this is a really simple process to follow. Scott Hanselman has all the details
complete with screenshots and instructions.
Me, I'm going to repave. In fact I never fully paved when I went to RC - I've been using Remote Desktop to get to other machines around the office that have Visual Studio etc installed. That was mostly because I'd been through two hard drive failures in as many months and was suspecting the controller was wonky. This drive has lived long enough that I'm willing to install stuff on it now, so there's plenty of installing in my future :)