Have a care.....before you rush off & purchase an XP disc. If you already have XP loaded on your PC it has a unique 'footprint/serial number' which has been recorded at Microsoft at activation. If you purchase another disc it will not be a duplicate of your original XP but an entirely new and individual edition of XP which if you use it will require activation in order to replace your original copy. What you should do is go back to your original supplier for an original copy of XP on your PC. If you are hell bent on purchasing another copy of XP then go for an OEM version it is much cheaper.