Is it possible to copy an app from Windows 8 and put it on Windows XP?
In a word, Bill – No. The Metro/Modern style apps for Windows 8 are specifically designed for that operating system. They generally work much better with touch screen devices.
If you want to keep Windows XP on your computer and still try out some of the Windows 8 Apps, you might consider buying a tablet that runs the Windows RT system. With recent price cuts, you can pick one of those up for around $300.
If you’re interested in upgrading to Windows 8, it’s possible your XP computer might be able to handle the upgrade. You can download the Windows Upgrade Assistant  for free and it will check to see if your current computer is compatible with Windows 8.
It’s a good time to think about upgrading your operating system. Windows is ending support for XP in April of 2014. That means no more security updates or bug fixes and that could leave your computer vulnerable.