Windows 10 Desktop refreshing constantly...until it suddenly stops

I upgraded from Windows 10 to Windows 7 about a month ago. Everything seemed to be working fine, although things seemed to be slowing down over the last week or so. Then yesterday the desktop and taskbar started endlessly refreshing so that I couldn't open anything. Managed to get the taskbar open and shut down the computer. Rebooted it and it started doing the same thing.

Eventually after we have been messing around with it for a while, it tends to suddenly stop and then I can use the computer. My husband disabled OneDrive, as we did some research online that said it can be a problem. We ran our ESET program to scan for malware. Neither of these things made the problem stopped. When the computer was shut down and rebooted, it went into that looping refresh thing. In fact, it was still doing it as I sat here registering for these forums on my phone, and then I noticed it had mysteriously stopped, so right now I am able to post this message via my laptop.

Usually when it is refreshing, it says 100% of the disk is being used under the disk tab on the taskbar. It may drop momentarily to 80% while refreshing, but then pops back up. When it finally stops refreshing for reasons unknown, it drops down to a range that fluctuates between 0% and 8%. Though probably a half hour before it stopped refreshing just now, it had dropped down to 0% and was still refreshing. There is nothing on the details listed under any of the tabs, cpu, disk, or otherwise, that appears to be chewing up a huge amount of resources. In fact, barely any resources seem to be being used at all in the details.

The only event that happened prior to this was that about a week ago we renewed our ESET subscription service, and everything seemed to be pretty much okay until now, except for slowness and a few instances of it not coming out of sleep mode right away...black screen, having to do a hard shutdown. My husband said the ESET scan last night showed some kind of boot errors, and I chalk it up to those instances. But my machine is almost four years old and was even slower on Windows 7. I do notice that since upgrading to Windows 10 minor settings and positionings seem to regularly glitch, like my browser magnifying to 500% suddenly, the cursor jumping sometimes, resulting in transposition of words or accidentally opening up things I didn't mean to.

But I've come to accept a certain amount of crap from computers over time, especially with Windows. Windows 7 worked the best out of any Windows product since XP. I lived through a horrible experience with Vista, and was just so happy to have a functional OS when I got a machine with 7 already on it. Though I was really aggravated when they released 8 right on the heels of 7. I had no interest in upgrading to 8, but for the past year or so, my system was harassing me more and more to switch to 10. I was so relieved that it still worked when I finally buckled after talking with multiple people about how seamless the upgrade was for them...but now a month in, and everything is screwed up and I probably can't even roll it back at this point.

Thanks in advance for any help you can give.

Kimberly