These keys should permissions for Administrators (Full Control and Read), Creator Owner (Special Permissions), Power Users (Read and Special Permissions), System Full (Control and Read), and Users (Read). These are the values on my computer.
Looking deeper Power Users has allow for all but Full Control, Create Link, Write DAC, and Write Owner. Users has allow for Query Value, Enumerate Subkeys, Notify, and Read Control.
There are a lot of keys in the registry that may be damaged. Do you have any set restore points? You might try going back to them and see what the permissions are and try a repair install. Did you run a registry cleaner? If so choose a restore point from before it was used? It might be time to flatten the box and reinstall a fresh operating system.
Douglas Lauritsen, Autodesk Product Support
We appreciate your quick feedback on this forum!
Well, just in case anybody else has this problem, we fixed it using subinacl.exe from microsoft
We now believe that the cause of this problem was a failed first installation of ACAD 2011. The first download of ACAD 2011 had a problem and caused the failed installation (don't remember the error now). We downloaded the software again and this time the instalation went well. But after that we begun having the registry rights and ownership problems.
Hope this can help somebody else.
Jorge