Can You Upgrade Windows XP to Windows 7?
Microsoft has made it clear that for anyone using the Windows XP (or older) operating system, there is no supported method of upgrading. You will need to perform a clean install to for Windows 7. Tests have shown that Windows 7 can run on low powered netbooks so it will probably run on older systems. By older, I mean systems built or purchased within the last 4-5 years.
Moving an XP system to Windows 7 will require a custom install. A custom installation gives the option to either completely replace your current operating system or install Windows on a specific drive or partition. Replacing your current operating system means starting from scratch. All settings will be lost and you must back up all your data. All your programs will also need to be reinstalled, as well. It is not guaranteed that all your XP programs will work with Windows 7.
In other words, if you want to use Windows 7, perform a new, clean install. Better yet, only install Windows 7 when you buy a new computer that comes with it pre-installed. You'll be glad you did.