Vista

For the easiest way to try Windows without killing your existing XP install, I recommend trying one of two approaches:

The first way is to simply make a backup of your existing Windows XP install and then install Windows Vista either over the top or as a clean install. If things go wrong or you choose […]

One concern for Windows XP users is if their favorite software applications will run once they upgrade to Vista.
Luckily, Windows Vista uses a feature called Compatibility Mode which tells the software application that Vista is actually an older OS, specifically Windows 95, 98, Me, NT, 2000, or XP.
Here’s how it works: