To Diagnose and Fix installation problems automatically, please see the new Microsoft tool for this here:
For more information on the Autodesk KB Support article concerning the clean uninstall of Autodesk products, see this link:
Then try a clean install again. Sorry for your woes.
2014 isn't supported fully on 8.1. Have you updated to the latest service pack for your product? That will go a long way in getting you compatible. You might also have to launch in Windows 8 or Windows 7 compatibility mode.
Start with some of our most frequented solutions or visit the Installation and Licensing Forum to get help installing your software.