Win XP uses an old version of UPDD V6, normally 433 or 522.
The Offline registration is slightly different for these older versions.
Please follow these instructions:
Do NOT enter the *purchase* information at the top of the screen. We don’t think this matters but this only applies for a new purchase.
Click enter a licence ke and Click OK.
At this point Offline is selected. Do not make a different selection and do not select offline again.
(Making a different selection cancels the offline registration and reverts back to offline auto order)
Now enter your license key and click OK
Copy the URL and paste to a browser on another machine, you should then get the registration key which you can then use on the XP system to register the licence.
We are sorry if this is a bit confusing but we re-designed the offline logic that only correctly works with releases of the software after the final XP releases