there is no upgrade path from windows xp to windows 7. You would need to backup any data you have and then do a fresh installation of windows 7. If a computer has a problem installing an operating system it probably has some defective component.
I think this is true only with Win XP 64.
Also I think a more appropriate link should be this: http://windows.microsoft.com/en-us/windows7/help/upgrading-from-windows-xp-to-windows-7