If your organization still having PC's running Windows XP then it's the call to you that Microsoft stops supporting Windows XP on April 8, 2014. Which means you won't receive any updates or support from Microsoft after April 8th, 2014.
* Up-gradation process may involve changing of your current hardware (as old hardware may not support running Windows 8).
* Up-gradation process may involve changing of your current hardware (as old hardware may not support running Windows 8).