I get the following error when trying to install Civil 3D 2012 XP SP3
Error 1406. Could not write value to key \Software\Classes\CLSID\{00020820-0000-0000-C000-000000000046}\InprocServer32\11.0.0.0. Verify that you have sufficient access to that key, or contact your support personnal.
Thanks
Faisal
You will be much better served posting this question in the Installation and Licensing forum.
Please try
http://usa.autodesk.com/getdoc/id=TS1069886
If this is due to an old Flash player, you can probably hit ignore about a dozen times and come out okay. Update your Flash player.
I'll confirm that this works, even though it seems like the wrong thing to do.
Well, being that I supported this issue multiple times a day as well as went onsite and experienced it myself on customer machines, I think you'll probably be alright. The issue is due to a problem that Macromedia had with an old version of Flash. You should consider upgrading your Adobe Flash plugins as well. Once you ignore those dozen or so 1406 errors, you'll be on your way.