I'm having this problem where my background display inexplicably begins to turn black. My background display is a beach scene and is replicated on both of my 2 displays. One by one, the background behind the icons on my screen turn black, square by square, until the background behind most of the icons is black, then some time later the entire screen (2 displays) turns black. I have been re-starting my computer repeatedly to temp-fix the issue but it's getting really annoying.

The issue first happened when I was multitabling the poker site Global Poker (which is a browser based application) with up to 10 tables so I figured there was some kind of graphics card overload issue caused by the poker site. Most of the subsequent instances of the issue have also occured when multitabling on that site.
However the issue has also happened when I'm not playing.

How should I trouble shoot this?
My PC is a custom build that I had done a year ago, never had any issues with it before with graphics or anything else.
The video card is Gigabyte - GeForce GT 1030 2 GB Low Profile Video Card.

Thank you for reading.

What version of Windows you running? Does it also say in the bottom-right corner 'this copy of windows is not valid' or something similar?

Oh, yes -- it says "activate windows >> go to settings to activate Windows" in the bottom right.
I never purchased Windows for this PC, I just use free open source software in place of Word/Excel.

If it's asking you to Activate Windows, then whoever sold you the computer probably didn't use a legitimate copy of Windows 10. If they're a reputable company, you can contact them and ask them about it. Otherwise you need to buy a license: cost is going to be $140 US from Microsoft directly, or $20 US if you want to go to a reseller (like g2deal).

Once you get Windows licensed, you'll get your background back.

Thanks for the info.
It's weird because I was able to go a year without needing to activate. I had this custom build done a year ago. Only time I would experience lack of functionality of Windows was them asking me to activate my license when I would open word or excel.