by boco » 17.11.2013, 02:35
WSUSOU doesn't upgrade Windows versions itself, it only installs patches.
For upgrading 8 to 8.1 offline you will need an 8.1 ISO/DVD. It is available on the internet, just Google.
Microsoft update catalog: http://catalog.update.microsoft.com/v7/site/
Windows Install media download: https://support.microsoft.com/en-us/help/15088/windows-create-installation-media