Question: When working I will have multiple windows of file explorer open at a time. If I than start working on something else and leave those windows open in the background, they will close themselves leaving only one of them open. I have tried going into task manager and restarting file exploiter and that didn't fix it. i am running Windows 10 pro. Does any one have any ideas on how to fix? 

Thank you!

Answer: 
If there's a network glitch, where a local Windows Explorer senses that a Network Share is no longer available, the OS WILL close Windows Explorer which was previously viewing said share. No error, no warning. 100% frustrating. Most users would prefer seeing an error with a REFRESH / RETRY option.
I had the same issue on a users machine, every time he opened file explorer it would just crash. He did get an Intel Optane error at first but after I uninstalled Intel Optane and rebooted that error went away, but the initial problem still persisted.

I eventually fixed it by setting explorer to open "This PC" instead of "Quick Access":

![enter image description here](https://i.stack.imgur.com/VljTE.jpg)