Earlier today I got an email from a fellow deployment geek having issues with Windows 8.1 deployments. He had an unattend file that worked perfect for Windows 7 deployments, but failed when deploying Windows 8.1. Now, it's simply comes down to that Windows 8.1 does not support all unattend.xml settings that Windows 7 does.
So far the most issues are caused by the IEWelcomeMessage or ShowMenuBar values being set. The solution, simply get rid of them.
- Start Windows System Image Manager (WSIM) and open your unattend.xml file.
- In WSIM, in the Answer File pane, expand the 4 specialize node, and select the amd64_Microsoft-Windows-IE-InternetExplorer_neutral entry.
- In the amd64_Microsoft-Windows-IE-InternetExplorer_neutral properties (right-hand window), right-click the IEWelcomeMessage property and select Revert Change.
- Repeat for ShowMenuBar setting in amd64_Microsoft-Windows-IE-InternetExplorer_neutral entry if needed.