Run the following commands hitting enter after each line:
net stop wuauserv
cd %systemroot%
ren SoftwareDistribution SoftwareDistribution.old
net start wuauserv
Reboot
Try updating.
**Important** The following issues occur when you do this:
Updates that are currently downloaded but that have not yet been installed have to be downloaded again by using Windows Update or Microsoft Update.
When you delete the Software Distribution folder, your download history is removed.
If you currently receive updates from Microsoft Update and from Windows Update, you will have to re-select this option from the Windows Update Web site.
**Note** If the issue is resolved and you can successfully download and install updates, you can safely delete the SoftwareDistribution.old directory to recover disk space.