Freeze during game

Hello, [vlad-salute] i have a problem with league of legends and my GF too. During a game after ~5-10 min the game freeze but i can still control my character and send him to the spawn with the map by clicking on it. But the video and the audio freeze. I need to open my task manager and close league of legends (lee sin style by pressing L and delete.) because the task manager is behind the freeze image of league.

_ System Model: MS-7917 Operating System: Windows 10 Famille 64-bit (10.0, Build 15063) BIOS: V1.13 Processor: Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz (8 CPUs), ~4.0GHz Memory: 16384MB RAM DirectX Version: DirectX 12

                 Card name: NVIDIA GeForce GTX 970

Sound Devices

        Description: Haut-parleurs +SSE3 (Realtek High Definition Audio) **(it's a steelseries headset)**

_

My graphic driver are update. But i have a steelseries driver for my audio.... But she doesn't have any driver or any kind on her pc. She have a gaming laptop GTX 960 (updated too) I5 8gb of ram Windows 10 is update as fuck.

Btw recently i completly reboot my pc but i still have this freeze. We repair the game too... But.. nah. Anyone with a solution ? :c please ?