This thread relates to - Install Error 0xC1900101-0x20017
If that isn't the error you received then please start a new thread.
C:$WINDOWS.~BT\Sources\Panther\setupact.log - Contains information about setup actions during the installation
C:$WINDOWS.~BT\Sources\Panther\setuperr.log - Contains information about setup errors during the installation.
These are the logs you need to look at or upload a copy to your SkyDrive account and post a link back for assistance.
I'd also suggest that you start a new post with exact details of your computer system (make/model)
Did you upgrade from a previous version of Windows to Windows 8 then try the update?
What steps you took before the upgrade - (reinstall Windows, reset Windows, etc)
Any errors encountered before attempting to update to Windows 8.1?