Have had three reports of this problem today. The reports are that the machines both physical and virtual show as 100% busy in Task Manager performance tab. The process with most utilisation may be svchost but this may not always be the case. It appears that it is windows automatic updates that seems to be the problem.
Solution – well in all cases the advice is to allow the updates to complete which may take several hours. Perhaps leave the machine on overnight to ensure that it completes. Reboot and check again for updates.