Hello There,

not to disappoint you, but upgrading isn't a good idea. It's better to jusr install the new OS on top of the old one, it'll get rid of all your programs, files etc., but it makes things much easier

make sure you backup all of your files!!!!

Hope i helped

Generally it "just works" and keeps all your stuff, but its a good idea to run the vista upgrade advisor (if you are upgrading from xp) to see if your system has any software or hardware which has known problems. As always, BACK UP as stuff can go wrong.

Some programs may need reinstalling but on the whole, they should be fine.

What I meant was when you are installing the OS from scratch, not upgrading. As in what most of you suggested, so it basically comes down to backing up everything and reinstalling everything !