Cleave

Opening Windows 7 in safe mode (F8 at startup) allowed me to copy/paste the serial # and make TMG happy as a puppy.

Don't know yet whether paste will work internally in normal mode.

It's a big club, apparently, with little consistency in fixes. Sooner or later we may stumble on the root solution. Interesting to note that the MS forum has 4 pages on this subject too.

Meanwhile, I'll add a little data: I have the problem on my Windows 7 desktop, but no problem on the windows 8.1 laptop. I've tried most (I think all) of the fixes suggested except using the safe mode which I'll try shortly. I can paste into other applications; so far TMG is the only one presenting me with the problem. I'm assuming if paste works in the safe mode TMG will be forever happy about my registration, and I can do most of my work on the laptop.

Dick