If for some reason you might wanna change your current Windows XP CD Key or after you discover that your current key is pirated or illegal but you don’t want to reinstall Windows XP from scratch and activate your new legal key, here are a few simple steps in order to change your Windows XP product Key without reinstalling windows.
Here’s how to change the Windows XP Product Key:
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_MACHINESoftwareMicrosoftWindowsNTCurrent VersionWPAEvents 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. In the text box in the Run window, type the following command and click OK.
12. When the Windows Product Activation window appears, choose Yes, I want to telephone a customer service representative to activate Windows and then click Next.
13.Click Change Product Key.
14.Type your new, valid Windows XP product key in the New key text boxes and then click Update.
15. If you’re taken back to the previous screen and prompted, choose Remind me later.
16. Restart your PC.
There you have it, and remember to always obtain your software legally to avoid problems like these in the future. =)