i was search why un4 freeze my pc
my pc is have i7 870 / ram 8g / gtx660ti / 600w / ssd 256g
problem is just start un4 5 or 10min just stop.
sometimes play particle system at 5 or 10min just stop.
and then i just push my pc reboot button.
i don’t understand because i have more 2 computer same product
plz help me
Hello feminchul,
When Unreal freezes your PC, what do you see? Is it a static image of the normal screen? Does the editor crash? Do you get an error of any sort? Does the screen go black?
If you’re not getting any of this information, can you please try monitoring your GPU/CPU usage and how hot they’re getting while the editor is running? It could be that one of your components is overheating.
Hello
Thank you for your answer.
i saw stop un4 editor and then all stop my PC.
i don’t have other error message from editor or PC.
now i’m going to try your solution.
i want fix my problem.
thank you .
i be in touch this post 
If you’re still experiencing this issue, could you please check this page and follow the steps? If you can send me the log that results from this process, I may be able to learn what is causing this problem.
hello mattew.
i have ue4 Crash Reporter now.
i just send a file to you .
my pc was work max2014, photoshop cs5, after effect cs5 and youtube play in chrome. and 4ea particle system run in UE4,
because i want see crash test my pc at run UE4.
my en level is very low i hope you catch my mean of post TT oT
can i waiting for your answer?
good day. 
Thank you for that information, feminchul. From looking at the log, this is the last message that is output:
LogD3D11RHI:Error: DXGI_ERROR_DEVICE_REMOVED failed
at D:\Build++UE4+Release-4.12+Compile\Sync\Engine\Source\Runtime\Windows\D3D11RHI\Private\Windows\WindowsD3D11Device.cpp:439
with error DXGI_ERROR_DEVICE_REMOVED DXGI_ERROR_DEVICE_HUNG
From looking at this message, it seems that your graphics card’s driver is crashing. This makes it look like the graphics card has been removed as the Driver acts as the bridge between the graphics card and the rest of the computer. While this does seem to be the reason this occurs, if your computer is freezing completely, this might not be the end of the problem. When a graphics driver crashes, it should be able to recover shortly after instead of freezing the computer. If it isn’t recovering, this could be a problem with another component in the computer such as the Motherboard or the Power Supply that is preventing it from recovering.
We haven’t heard from you in a while, feminchul. Are you still experiencing this issue? If so, was my last comment of any help? In the meantime, I’ll be marking this issue as resolved for tracking purposes.
Hi Matthew i’m sorry i had have busy and take a vacation. i tried your answer but i don’t fix that issue. so i send my graphics card’s for nvdia a/s center lest week.
because i’m re install my window and graphic driver. i had double checked. first gtx450 second gtx660ti. that problem look only gtx660ti. i thought and i hope just only my graphics card’s trouble. thankyou for your service ^^;;; i definitely comment this page. how can fixed this issue. plz for give me below luck haha.
good day Matthew. i be in touch!!!