I finally did figure out the Windows Update failure that I’ve had forever. I was getting Windows Update error 8024402C and I tried every suggested solution I could find (Microsoft Fixit, Windows Upgrade Preparedness Tool, editing registry entries, deleting xml files), everything short of re-installing Windows.
Rather than re-install Windows 7, I thought that upgrading to Windows 8 would surely do the trick. Windows 8 couldn’t check for updates either!
I don’t remember exactly what the little note on the Windows 8 Update dialog was, but it gave me enough of a hint to find the solution. The Windows 7 laptop in question had been joined to a corporate domain at one time, and received (unbeknownst to me) a group policy setting that it should get its updates from a corporate server rather than from Microsoft. Of course after being removed from the domain and disconnected from the corporate network, it couldn’t find the updates any more. The Windows 7 error messages were useless in locating this simple but obscure problem. All I got was a notice that I needed a new version of Windows Update and error 8024402C when I tried to get it.
To fix this, go to the Control Panel and search for "Group Policy". Select “Edit Group Policy.” Expand the tree to Local Computer Policy > Computer Configuration > Administrative Templates > Windows Components > Windows Update and remove any configurations there, especially one for “Configure Automatic Updates.”
A decent error message would have saved me many hours of frustration; I hope this article helps you to avoid that.