Not sure if this will help.
If you have formatted using WinXP you have probably formatted with NTFS or FAT32. Most flash memory seems to use FAT (FAT16). You may be able to reformat in the correct format. Not sure how this would be done under WinXP,don't use it, but someone else might. Anyway will put you back to top.
You might like to check which FAT you have and what is required.Do you have administrative tools in XP?
Is it password protected? The instruction suggest going back to your dealer if this is forgotten.I assume you have the instruction book which can be found here.
You also might like to try their support line here.
Regards Brian j