Every game I play crashes on my brand new PC

[DrewSpr]

So I'm going to start off with saying that I am no expert when it comes to PC's. My friend built this one for me and ever since we finished it has been having problems playing games. For example with steam, I will be playing Total War Shogun 2 and it will randomly crash during a session with the message "Total War has stopped working". It doesn't happen during any big action scenes or whatever, it seems completely random. This is happening to all my steam games and for League of Legends as well. When I play league I get at least two bugsplat's a game and again, they take me by surprise. We have tried a lot but this may be beyond us. Please help me as this is my first experience with pc gaming and is pretty frustrating right now
Specs:
NVIDIA Geforce GTX 970
Windows 10 64bit
EVGA supernova NEX750B
16G of ram
1TB HD
MSI Z97 Gaming 5 motherboard
Intel Core i7-4790 CPU @ 3.60 GHz

 

[Tmagic650]

Have you applied all the Windows Updates and the Nvidia drivers to the latest Windows 10?

 

[DrewSpr]

My windows updates are current. For the Nvidia drivers, I have the most recent one but do I need to install them all?

 

[Cycloid Torus]

Hmmm. it could be practically anything...hmmm....

Best idea - run tests - catch error messages
memtest overnight ... http://www.memtest86.com/
Turn off 'restart on error', so you can get a good look at any error messages.
Check Event Viewer for errors just before crash. http://www.computerhope.com/jargon/e/evenview.htm
Consider using WhoCrashed... http://www.resplendence.com/whocrashed
Check SMART for your HDD... run chkdsk /f (in Properties of HDD in File Explorer) - read detail in event viewer