No problem.
Here's how you can fix it in less than 15 min.
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
If you're uncomfortable making registry changes, check out the tip at the bottom of the page.
1. Click on Start and then Run.
2. In the text box in the Run window, type regedit and click OK. This will open the Registry Editor program.
3. Locate the HKEY_LOCAL_MACHINE folder under My Computer and click on the (+) sign next the folder name to expand the folder.
4. Continue to expand folders until you reach the HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\Current Version\WPAEvents registry key.
5. Click on the WPAEvents folder.
6. In the results that appear in the window on the right, locate OOBETimer.
7. Right-click on the OOBETimer entry and choose Modify from the resulting menu.
8. Change at least one digit in the Value data text box and click OK. This will deactivate Windows XP.
9. Click on Start and then Run.
10. Continue with steps how to change Windows XP registration key here
