No activity while trying to re-install the program 123D

Hi friends,
I wanted to take out 123D and do a clean install because there was an installation error the first time round.
When I try and uninstall it using the autodesk, there is no activity, I mean, it just does nothing. Is there a file specifically for uninstalling this program cleanly, which would take out all the registry files in order to do a clean install?
If I try and run the installer again, it shows that the product is already on my system.
I am running win 7×64. Screenshot of the error:

Autodesk 123D Installer
Could not open key:
UNKNOWN2225EE2FC2780DA409169A8AE99BDC609AF
6AEDE7B82CE84681C12BB761D9E9A. Verify that you have sufficient
access to that key, or contact your support personnel.
Please give me help.
Thank you people.
