All applications are crashing every 30 minutes or so  

Thank you RolandJS..... this is what I was getting at, referring to! Get rid of this application----> Segurazo

Hopefully, you can read this: 8 ways to boot into Windows 10 Safe Mode | Digital Citizen

Thanks, Jacee. I am able to boot into safe mode with networking, but when I do it won't connect to the internet. I get a windw saying, "It looks like you're not connected to the internet. Let's fix that. Run troubleshooter." When I run the troubleshooter it says "network diagnostics cannot be run in safe mode. Reboot your computer to exit safe mode." But I don't have any problem connecting to the internet when I boot up normally. It just won't connect to the internet when I boot into safe mode. The instructions say to boot into safe mode first and then download Malwarebytes, but is there any reason I can't just download Malwarebytes in regular mode and then boot into safe mode to run it? Basically reverse steps 1 and 2?

See if you can download Malwarebytes normally, update the definitions, then boot into safe mode to run it.

I next tried booting to safe mode (selecting F5, Safe Mode with Networking), but it is not connecting to the internet

1. The first point about booting to Safe Mode was simply to see whether you experienced any crashes. Try booting to Safe Mode (any form), leaving it long enough, and report if any crashes occur.

2. That you can't connect to the internet suggests there is indeed something fundamentally wrong anyway.

3. Whilst you can try an in-place upgrade repair install which keeps all progs and data, and for which you need an iso (or bootable disk) of the same build as you have (tutorial available) I suspect, unless it proves to be hardware which we're doing our best to eliminate, I'm guessing you're heading for a clean install. That is justified inasmuch as you see the same problem logged in as a new user.

4. There's one other check you should do to determine experientially if there's a hardware problem- download, create and boot from Kyhi's live boot disk (Win 10).
Toolkit Item: Kyhi’s Rescue Disk – Win10.Guru

If your PC still crashes running that- it's got to be hardware, and there's no point trying to fix the software.

You're welcome