The only other thing I would think to try is to again remove Revit using the Microsoft Fix It utility then reinstall following the steps from the following document.
I had exactelly the same problem with autodesk robot structural analysis 2013. The only solution that I have found after two weeks of test is to reinstall windows. After every thing has working well. Perhaps a windows repair with CD is possible, or with the sauvergard initial CD of your computer.
Unfortunetly it's a lot of work to reinstall all yours softwares.
If somebody has a better solution it will be great
no danny that didn't work for me...thanks for giving me yr valuable time...now i have give up.....
and thanks pierreFINELS6147 for that solution....but i dont want to reinstall windows..as u said its lot of work to istall other program.....but thanks