how to activate win xp when no product key is available

1. Right Click on My Computer and Select Properties.

2. Wait a second for windows activation details to get populated.

3. Click on Change Product key link after your Windows 7 activation details are populated.

Answered Oct, 13 2010

1. Open regedit and goto:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\10.0\Registration
2. Under "Registration" key, you'll see one or more GUID (Globally Unique IDentifiers) containing a combination of alphanumeric characters in following format:

{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
3. Select each key and look at "ProductName" key in right-side pane. One GUID key will contain the version number of Office installed in your system "Microsoft Office XP Professional Edition".
4. Select that GUID key and delete following 2 registry entries from right-side pane:

DigitalProductID
ProductID
5. Close registry editor and run any Office application e.g. word, excel, etc. It should prompt you to enter a new product key.
6. Enter the desired product key and click on OK. That's it. Answered Apr, 08 2011

This article describes how to change the Windows XP product key after a Volume Licensing installation. You can use the Windows Activation Wizard graphical user interface (GUI) or a Windows Management Instrumentation (WMI) script. The Activation Wizard method is easier, but if you must change the product key for multiple computers, the script method is better.

Read more : http://www.wikihow.com/Change-a-Windows-XP-Product-Key Answered Apr, 11 2011