If you are Windows XP user then you might want to check Windows 7 transformation pack for XP , this transformation Pack will convert your XP completely into Windows 7 Look. But if you are looking to get only Windows 7 theme for Windows XP, then follow the below article:
A Deviant Art user has released a Windows 7 theme, that can be used for Windows XP. The theme looks really beautiful and definitely gives Windows XP a much needed facelift.
below is the preview of this theme:
You can use the following link to Download this theme:
Also take a look @ Windows XP Theme Section for more themes
