UPDATE: This bypass method described below doesn’t work anymore. Visit mydigitallife’s article for an updated (3-dec-2006) and easy method of bypassing WGA/Notifications/Visiting Windows Updates, etc.

In 2005 Microsoft introduced Windows Genuine Advantage (WGA) which was (also) meant to reduce illegal copies. Since then, people who had an ‘illegal’ Corporate copy of Windows XP or Server 2003 were not able to use the Windowsupdate site anymore.
Shortly after that people found a way to bypass the checks required by the Windowsupdate site by disabling the WGA ActiveX plugin from their Internet Explorer.
It could be done by pasting this line in your browser:
javascript:void(window.g_sDisableWGACheck='all');
Microsoft fixed it and bypassing was no longer possible after March 2005.

The following content is for informational and educational purposes only.

I came accross the website of djlizard and he found a NEW way to bypass the checks at the Windowsupdate site.

  1. Close all your browsers (this is really important)
  2. Click Start -> Run -> Type: regsvr32 /u LegitCheckControl.dll
  3. Go to the WindowsUpdate site, select typical or custom. It will show the Activate button to activate your copy of windows. Click Start -> Run -> Type: regsvr32 LegitCheckControl.dll and go back one page in your browser. Now you can click typical or custom again and it won’t show the Activate button but continues to search for updates.