You may get error 8024A000 when checking for updates with Windows Update.

If you have recently changed your partition layout (resizing) or put in a new HD, you may get this error. The solution that seemed to work in my case, is to download and install the latest Intel Rapid Storage Technology driver (I know, what has this got to do with Windows Update, right?). After installation, Windows redetects the disks and, for some reason, Windows Update suddenly comes to life again.