Display Driver Stopped Responding

"Display Driver Stopped Responding and has recovered." I know this is not a unique problem since I can find it all over this and other forums, but none of the fixes I've tried have worked, and no situations I've read about are like mine.

This is a problem that occurred two or three times over a one-year period since I built my unit--nothing to really complain about. Usually the screen went black for a second, recovered, and I was on my way. But like a number of problems I'm dealing with now, it has gotten much worse since I upgraded to Windows 10 and subsequently had to abandon that hard drive and go back Windows 7 on a new hard drive a couple months ago.

It still wasn't a huge issue until this morning, when it has occurred over and over, and now it often doesn't recover: the monitor goes to sleep and all I can do is turn the computer off and on to start over. My GPU is a NVIDIA GeForce 760, and I have uninstalled the old drivers, reinstalled new ones with a clean install, and this makes no difference. (In fact, I've done this several times, with different driver versions.)

What have I done recently that could make a sudden change? I've included some add-ons to my web browser, but I took those off just in case. I installed an SSD this weekend, which the computer fully recognizes, and which I plan to eventually use to hold programs, but right now it's just empty, one of three hard drives.

I'd be grateful for any ideas. By the way, all I'm trying to do is work on Word documents. I do video editing at times, but at the moment I'm just trying to respond to my students essays, with all other programs closed.

Thanks for this. I think I have a bigger problem. I'm going to start a new thread.