Just in case you still have some applications that demand XP.
Running Windows 7? Missing the old familiar stench of XP? If you're running Windows 7 Professional or Ultimate, you'll be able to get back the old-car smell with Windows XP mode – provided that you've got the right virtualization-supporting hardware.
Just in time for the release of Windows 7 worldwide, Microsoft has posted installation instructions and release notes for Windows Virtual PC and Windows XP Mode. You can download both right here.
Of course, after familiarizing yourself with the installation, you'll need the actual XP Mode or Virtual PC software. That can be had from Microsoft as a free download right here.
Let us know if you manage to get it running and how it feels to have some old inside the new!