Odd, unless it is the motherboard, I would think it seems more like malware or virus or a bad program. Those components, otherwise, really aren't connected.
You could try starting up in "Safe Mode" or "Safe Mode with Networking" and see if the problem occurs there. If it does, then we are talking hardware. If it doesn't, then I would do good scans of the computer.
How to enter "Safe Mode" when booting the computer.
In Windows 8 and 10...
As your computer restarts, press F8 (possibly a few times) to enter "Safe Mode"
a. Press the "F4" key to Enable "Safe Mode".
(The computer will then start in "Safe Mode" with a minimal set of drivers and services.)
b. Press the "F5" key to Enable "Safe Mode" with Networking.
( Once "Safe Mode"...