Recently I tried to install COM4 game (Call of duty 4 modern warfare). After that speakers and earphones in my pc are not working. When I open computer management>Device manager>sound,video and game controllers> The sound device status is showing as 

"Windows cannot verify the digital signature for the drivers required for this device. A recent hardware or software change might have installed a file that is signed incorrectly or damaged, or that might be malicious software from an unknown source. (Code 52)"

And also a error (yellow) symbol is shown on the driver

Hoping for a early reply

hello,

Download the latest driver and install it on your computer

Where can I get the latest drivers? I lost my windows 8 Drivers CD

Hi,

Go to the device manufacturers Web site and download and install the latest appropriate driver for the device.

More information, please read this article:

Code 52: Windows cannot verify the digital signature for the drivers required for this device

https://technet.microsoft.com/en-us/library/ff710454(v=ws.10).aspx