This will allow you to bypass the Microsoft Genuine Validation thing by this method works better than many others I've tried before.
forget the cracks and injectors etc... this is the BEST WAY
1) start > run > "regedit" (without the quotes of course)
2) go to the key:
HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\Windows NT\CurrentVersion\WPAEvents\OOBETimer and doubleclick on it.
Then change some of the value data to ANYTHING ELSE...delete some, add some letters...just change it!now close out regedit.
3) go to start > run > "%systemroot%\system32\oobe\msoobe.exe /a" (again, dont type the quotes)
4) the activation screen will come up, click on register over telephone, then click on CHANGE PRODUCT KEY, enter in this key: JG28K-H9Q7X-BH6W4-3PDCQ-6XBFJ.
Now you can do all the updates without activating,
and the Genuine Microsoft Validation won't bug you no more!!
Works with most WinXP versions though there are some exceptions...