As a salesman at a computer retail store, I had to take a number of Windows 7 training classes. There is no direct upgrade path from Windows XP to Windows 7. You have to do back up all your data then do a clean install of Windows 7. You can upgrade from Windows Vista without a clean install as long as you upgrade to the same type; Vista Home Premium to Win 7 Home Premium, Vista Business to Win 7 Professional and Vista Ultimate to Win 7 Ultimate. You also have to upgrade from 32-bit to 32-bit or 64-bit to 64-bit.
Here is a link about Win XP to Win 7: http://www.pcworld.com/article/174282/five_things_you_should_know_about_upgrading_from_xp_to_windows_7.html
Microsoft has the "Windows 7 Upgrade Advisor" that will tell you if your PC is compatible with Win 7. Get it here: http://www.microsoft.com/windows/windows-7/get/upgrade-advisor.aspx
Sorry, only students may add comments.
Click here for more
information on how you can set up an account.