I will recommend you to uninstall the video card driver and install the latest version directly from the Nvidia that might help you. 

Can you please advise which driver i have to download? cause i have this issue also

i've download from nvidia web 850M(Notebook) driver but it said not compatible with hardware.

that is funny, you've recommend but didn't provided any link for us

Try this one.  

I assume you have a 13 with a Broadwell CPU if Nvidia's latest doesn't work.

Download the Nvidia driver on the 15 / 17 R2's support page. The one on the 13's page is too outdated and won't work, but the ones on the 15 and 17 R2's page will work (I've used such driver before).

yes, that is the one i try to install yesterday.

it said no compatible hardware found

No luck. Installed but still having sound and video skipping issue. Any other suggestion? I am really "GERGEGGER"" sound while playing COD:AW.

Any Feedback?

Is this happening only with COD:AW?

youtube. Even Windows logging sound effect as well. [:@]