Windows 10 randomly changing theme to very basic

[Zachattack5449]

So lately, while playing Call Of Duty BO2, my computer freezes up, and change the theme from the regular windows 10, to windows 7 "Very Basic". This sometimes happens with a series of beeps, up to about 10, usually only about 3-5. This computer only had windows 10, and I didn't upgrade, so I don't know how it even has that theme. I know this because when I have my 2 extra monitors on, and the game freezes, I can see the outline of the file explorer change from the regular windows 10 theme. Is there any fix, or any known cause?

 

[Colif]

what are specs of PC?

Beep codes normally associated with the motherboard so would help tyo know what you have