This is the Windows Server Update Services support team blog. We cover all things relating to WSUS and Windows Update.
I didn't see this documented anywhere so I figured it would possibly help someone out of a jam. If you're seeing 0x80070070 errors on any of your clients then you'll want to check this out:
Issue: When going to the Windows Update page you may receive the following error message:
Windows Update has encountered a problem and cannot display the requested page. 0X80070070.
Download Failed. Result code: 0x80070070
Hmmm, not much help there unless you know that 0x80070070 means ERROR_DISK_FULL, which you probably don't.
Cause: Obviously this can be caused if you don't have enough free space on your drive, but it can also be caused because disk quotas are enabled and you're over the limit.
Resolution: You need to either free up some disk space or you need to adjust or disable your disk quotas. To free up disk space you can run something like Disk Cleanup, and to adjust the Disk Quotas see http://technet2.microsoft.com/windowsserver/en/library/3b5b242b-7bb2-48e4-8e5f-224a08b36b271033.mspx?mfr=true.
Hope this helps,
J.C. Hornbeck | Manageability Knowledge Engineer