This works, but it's not a permanent fix - moving one of these windows off the main window results in this situation every time - have to go through this process each time I forget that moving a window off causes this error. Docked windows seem to be OK.
Those buttons also don't work once the system loses track of the separate windows or maps them to a location off the screen. I found that only resetting the normal.mxt file works in this case.
In my case, I suspect this is from poor handling of a high-resolution display by some configuration setting in Arc (2880 x 1620, 10.2, Win7), but I haven't been able to get a response on this issue yet that fixes it permanently. It's a real nuisance to be totally locked out and have to reset the normal.mxt to get control back.
I cannot get my table of contents, search window, or catalog to show up in arcmap. One day it worked next day wont show. I have gone to windows tab and clicked on th toolbar but still wont show. The python window and model builder will show up when clicking icons on tool bar but the others wont. Does anybody know how I can fix this?