This will all depend on wether or not you Fully Formated the Hard Drive before you Installed Windows XP Home Edition.
See, Windows Vista Uses A Partitioned Section of your Hard Drive to Store Critical Operating System Information. Although this is not a Mass Amount of Information, it's Information that Recovery Discs Need To Boot into an Operating System. So in short, if you have Totally Wiped the drive clean when you Installed XP Pro, then you'll ptobably find your Recovery Disc Useless. See OEM Software like Recovery Discs dont usally come with Serial Numbers like Original Windows Operating System Discs come with. So the information of the Registered Owner of a PC which comes with Pre-Installed Software, is Stored on the Hard Drive and Hidden in the Registry. In order to get Vista Back on your Laptop.
If you manage to get your hands on an a Copy of Windows Vista, then the link below leads to Microsofts Website and Provides a Guide on How To Upgrade to Vista from Windows XP.
Hope this Helps