Solved! Go to Solution.
What happens if you create a new local administrator account, log in using this new account and start AutoCAD (do not migrate custom settings if asked - click Cancel instead)?
If this does not work I suggest performing a clean install:
And make sure that the user installing/uninstalling and using the product have enough rights to do so (install and reinstall as local administrator):
Unable to run AutoCAD® as a restricted user http://usa.autodesk.com/getdoc/id=TS1055299
Product Support Specialist