http://www.mydigitallife.info/2006/10/27/windows-defender-final-free-download-and-install-bypassing-wga-validation-crack/

1. Download Windows Defender from the above link, and save it to a convenient location (For example below, we use C:\ drive).
2. Go to Start -> Run.
3. Key in the full path to your Windows Defender setup file including the name of the setup file (e.g. C:\WindowsDefender.msi if the MSI installer is located in C:\ drive).
4. Append and add the -qr to the end of the line. The complete command will look like this:C:\WindowsDefender.msi -qr
5. Press Enter or Click OK.
6. Wait for Windows Defender installation to complete.

After trying this method has it worked for updating Winxp :

Many thanks thank you:

Does this work yo only this msi or any msi package that has validation check?

Thanks!!