Hello there. Got a quetion that is bothring me for a a while. Hope someone can help!

I had used a crappy CD to install Windows XP Pro on my machine (you know what I mean by crappy) but I shelled out a load of cash last night and got me some real Windows XP Pro CD. Feels good. Anyway, I sort of thought that when I insert the new CD it would just overwrite the OS and leave all my mail, firewall etc etc in place as is. However it gives me a message saying "Cannot upgrade this version of Windows" ...i.e., I only get the option to install a FRESH windows xp.

Is there any way in which I can reinstall my real Windows XP and still retain all my programs and configs from the old setup I have been test-driving since 4-5 months?

Thanks!