I am a new user of ACA 2013. i HAVE JUST STARTED A TUTORIAL, "... NO EXPERIENCE REQUIRED".
YESTERDAY I LOST THE COMMAND LINE, THE TABS AND THE RIBBON.
HOW CAN I GET THEM BACK.
The easiest way to restore ACA is from Windows start menu, under All Programs->Autodesk->Version Folder, select Reset Settings to Default. Warning, any customization you did will be lost.
For the future please start a new thread with your issue, instead of piggybacking on old threads.
Normal people believe that if it ain't broke, don't fix it.
Software Engineers believe that if it ain't broke, it doesn't have enough features yet.