Screen freezes while playing?

Love community,

For a month now, my screen freezes when I enter a round of League of Legends. This was my speaker broken and then I have brought my laptop for repair. Today I wanted to play a round again and the same problem has occurred again. My PC is freezed, I usually press the power button and then it starts normally again.

Does that happen with other programs and tasks? Or only with LoL?

Try running the prime95 program, this is a benchmark stress test for the CPU (processor). Does he also get stuck?

maybe you should also run the program memtest86 times (tests the memory).

If both of these things are fine, then the third thing I'll be typing is a problem with the graphics card.

does this only happen on battery power, only in mains operation or both?

At World of Warcraft also and then get so blue screens mmcsss.sys as error message or other things

Please try the other hints still out.
1) prime95 and memtest86
2) battery and mains operation with laptop

so you can possibly narrow down the problem.

it may help synonymous sometimes the latest drivers to install or reinstall the drivers. Chipset driver, usb driver, graphics driver.