Try the following:
Run command prompt as administrator.
In CMD, run ‘net stop wuauserv’, then run ‘net stop bits’.
Navigate to C:\Windows\SoftwareDistribution\Download.
Either rename SoftwareDistribution\Download to retain its contents, or you delete all files and folders contained within SoftwareDistribution\Download.
In CMD (again with admin privileges) run ‘net start wuauserv’, then run ‘net start bits’.