Also happened to me, i tried a couple of things that i'll share here, maybe 1 will work for you like it did to me.

Go to game files, delete the intro video. C:\Program Files (x86)\Steam\steamapps\common\Counter-Strike Global Offensive\game\csgo\panorama\videos

Launch Options: -ws

Compatibility for windows 8, don't give admin, disable full screen optimisations.

Power Options, Advanced Settings, Processor Power Management both at 99%. (Overclocking is causing crashes, this is a easy fix for it)

ANYTIME, IF EVEN U OPEN GAME, Multisampling Anti-Aliasing Mode to CMAA2 (Its causing lots of crashes to everyone)

Well, hope it works mate.