You don't need a download. Step #2 below will install mixers.
1) -Make sure speakers are not muted.
2) -Make sure Windows Audio Service is set to Automatic & Started. (Run services.msc) - Scroll down to Windows audio - double click.
3) -Download & save to your desktop, Audio drivers for your computer model and Operating System from your Computer MFG Site. (Do not Install yet)
4) -Uninstall Audio Drivers in Device manager & Reboot.
5) -When new hardware is detected, point to desktop for drivers.