Upgrade XP2 to XP3 Using regedit

No need to download win Xp3...
Hassle Free

Here we go...

Steps:

1. Open the Registry Editor.
2. Navigate to the key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Windows



3. Double-click the DWORD value CSDVersion and change the value data from 200 to 300.
4. Click OK.



5. Close the Registry Editor.
6. Reboot the machine.