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: 
**Possibility #1**

If the folder is deleted or moved explorer windows will close themselves. Are these folders being manipulated in anyway?

**Possibility #2**

The other possibility is explorer having too many files open at once. A good fix for this is to enable "Launch folder Windows in a separate Process". It's a little know feature of windows that allows the machine to separate file/folder access from the Explorer GUI process (been around since XP).

It can be found under Control Panel > File Explorer Options > "View" Tab > Launch folder Windows in a separate Process

**Possibility #3**

Alternatively, you can check to make sure that explorer hasn't become corrupted.

1. Launch an administrator commandline (Win + X) -> Press "A"
2. Click yes to accept the UAC prompt
3. Type this command "sfc /scannow" (without the quotes)

Windows will scan all of its core files and fix any problem it finds. I am an IT professional and explorer generally starts to behave after theses steps have been exhausted.
I've had some users complaining about this happening.
After seeing the issue by myself, I started searching for the cause.
I opened three Explorer Windows, one with the local C: drive, one with the profile mapped homeshare and one with the commonly used data storage share drive.

The only window, which was closing occasionally, was the one with the common data storage, which lead me to the conclusion, that I should have a look at the GPOs.

Forcing a GPUPDATE reproduced the issue and I started searching on the net where I found this thread here.

The solution was exactly what user1084330 described.
Setting "Replace" to "Update" on the affected GPO solved the issue at the second GPUPDATE.