Run Windows Update Troubleshooter works on RT too.
http://windows.microsoft.com/en-us/windows/troubleshoot-problems-installing-updates#1TC=windows-8
Win RT will do PowerShell so this might work also : Read through some of the comments for tips that might help.
http://answers.microsoft.com/en-us/...4072-bfcc-3b41c1717f6d?rtAction=1382172522816