Hey again ,
If you are using the “Update Driver…” button within the Device Manager of Windows, you will usually not find the update. Your driver is actually out of date according to the Realtek website. I actually updated mine recently with this driver as well.
Realtek Audio Drivers
http://www.realtek.com.tw/downloads/downloadsview.aspx?Langid=1&PNid=14&PFid=24&Level=4&Conn=3&DownTypeID=3&GetDown=false#1
Download the new driver for the Windows 64-bit and then check to see if this helps your issue. Definitely restart your computer after updating your driver. Let me know what the outcome is after doing so, and if you still need help.
Cheers,