I protected some cells last night for the first time. I can see why "select all" is not a key you want to hit with some protected cells in a worksheet, but I wasn't thinking and I hit it. (I hit the cell to the left of "A".) The cells turned blue, as they should. But when I clicked on the command I wanted to use, everything froze. There began 2 hours of frustration. I was eventually able to get back into the file (which appears to be undamaged), and used "Save as" to make a dummy file to duplicate the malfunction and try to figure out what was going on. The problem persists. I CAN go to "Format," "Unprotect sheet" to prevent the problem, but that's not a very useful workaround. I would be happy provide more details, but I have a hunch someone reading this will know exactly what happened without needing any. Thanks