Since putting some Windows 8 machines in my domain, I’ve noticed that they will not get updates from our internal WSUS server. I did some searching and found this Microsoft KB article:
Issues that are fixed
This update lets servers that are running Windows Server Update Services (WSUS) 3.0 SP2 provide updates to computers that are running Windows 8 or Windows Server 2012.
Read the full article of course, but if you’re just running a single server as we are, the process is to download the patch, install it on your WSUS 3.0 SP2 server, then run a sync. If you have already attempted to attach Windows 8 clients and received the 800B0001 error, you will need to stop the Windows Update service, remove the Windows\SoftwareDistribution directory, and start the Windows Update service again.
Works like a charm!