Computer completely freezes except mouse and sound

Occasionally my computer will freeze and I'm not sure why. I'll have Chrome on one monitor and Rainbow Six on the other. I'd switch when there's downtime and randomly it'll freeze. I can hear the game sounds and move my mouse but I can't exit anything and have to do a hard restart.

Anyone have any idea why? It'll happen randomly and occasionally.

Just a few minutes ago, I tried to run Rainbow 6 while watching Netflix in the background. The game opened and started to load in and then my computer froze. I could move my mouse and still hear the show on Netflix continue as usual. The Rainbow 6 sounds as well. I could move my mouse but I couldn't exit anything or open task manager.

I have had to do 4 hard restarts this week... I tried other subreddits and no response :(! Hopefully you guys can help.

Motherboard: MSI Z97S SLI Krait Edition (MS-7922)

Processor: Intel Core i5-4590

Graphics: NVIDIA GeForce GTX 950

SSD: Samsung SSD 850 EVO 250GB

HDD: WDC WD10EZEX-00BN5A0

Power Supply: Corsair 600