It's showing large amounts of memory errors - it should be showing "Errors: 0"

Try re-seating the RAM module(s) to start with, a dirty or tarnished connection can cause problems.

Wipe the gold connector edges on the RAM modules with a bit of folded paper - just normal plain white printer / letter paper.

That's just abrasive enough to remove tarnish without damaging the gold plating.

Be very careful not to snag any component on the modules!

If it still shows errors and has two modules, try with each fitted on it's own.

If both show similar errors it's likely a motherboard fault or the CPU needs reseating..

You're looking for errors, and it looks like you've gotten quite a few. That and the problem you've described pretty much spell out bad RAM.

Simply put, if your run across errors during Memtest, it likely means one or more of your RAM modules is faulty.

So now what you should do is try removing your RAM sticks one by one to see if you can pinpoint which one is bad. If you only have stick, put it into your other RAM slot if you have one.

Hopefully, you'll eventually isolate the bad RAM and figure out what you need to replace.

Memtest86 will show an error message if something is wrong with your RAM. It tests the memory several different ways and a complete test can take hours, but it won't show if your hard drive is corrupt or anything else is wrong with the PC.

Did someone replace the RAM in the computer? It looks like it is not compatible.

If it is a laptop it is possible that it needs lower voltage 1.35v RAM instead of 1.5v RAM. I ran into that recently, Win10 worked, but not for long before memory errors. If you still have the old RAM see if it has an L on it (like DDR3L or PC3L). But some websites or packages for low voltage RAM do not mention the L, they only show the 1.35v.

It's a memory test. If it finds a problem with your memory hardware it will display a clear meaaage saying so. You can stop the test at any point. Memory failures are uncommon these days.