You obviously have two screens. Have you adjusted the aspect ration and resolution seperately? Click on either screen 1 or screen 2 in display settings and tweak them to your liking.

Secondly, are you sure you didn't hit a button somewhere on the monitor itself?

I can't see anything to 'tweak' on the page that allows to toggle between screen 1 and 2. Resolution is the same for both monitors.

You can do it all through display settings (Settings/System/Display).

Two diagrams of monitors at top of page. One or the other should be darkened. This is the active monitor.
Scroll down until you come to Scale and Layout. Whichever monitor is darkened (highlighted) is the active settings.

The optimum resolution for each monitor will be marked. (Recommended). They can be changed independently.

1024 x 768 is a 4:3 aspect ratio. Can you set the resolutions to 1920 x 1080, or 1280 x 720, or 1366 x 768? (Just try the highest available 16:9 aspect resolution and if you don't like the results, wait for the computer to revert back to your current setting (30 seconds or so), and try another resolution.)

My problem may be I need to make more than one change to get this to work right again, and I'm not changing but one thing at a time.

The TV is 16x9, but the small monitor is a 4x3.

Everything was fine until it wasn't.

This page has lists of resolutions for 16: 9 and 4:3.

http://natesbox.com/blog/43-and-169-screen-resolutions/

see my reply to Make7 for what I did.

Y'all were both helpful, and I appreciate your time.

Leave the monitor at 1024 x 768 and change the TV to 1366 x 768.

If you right-click on the desktop and choose screen resolution, in the control panel that comes up, I think you just click on the numbered monitor icon at the top to select and change settings individually.

It's back to looking right again.

I changed to using only the TV, got the resolution like you recommended, and the display is much better. Then I went back to both displays and the computer changed the TV resolution to match the monitor, which is what was stretching the picture. Changing the TV resolution back to 1366x768 held and now it's keeping the aspect to what it should.

Thanks a whole bunch!

Plus I learned something that may make it possible to use my Windows 10 computer the same way. I tried the 10 on the TV while the W7 was in the shop and couldn't make it work.

You could just put a text file on your desktop with the resolution settings that work best in case something changes. Especially when you sort it out on your Windows 10 machine. Sometimes just unplugging a monitor temporarily makes the display settings revert back to some previous setting even after that monitor is plugged back in. Thanks, Microsoft.

does it?

you're missing screen space.

I already had the type set to 150%.

In spite of my incompetence, I learned something new. I have always said you don't learn much when these things work properly, but get things out of whack and sooner or later, you learn new tricks.