if audio input and output are not working with Realtek audio driver then the top 2 most reasons might occur.
Top1 Reason: Your Audio Enhancement Driver Issue.
Your system’s audio input and output might not work due to the audio enhancement driver issue in your system
you need to update your audio drivers or uninstall and download the fresh Realtek audio driver from here.
it’s quite possible that it will resolve by updating your Realtek driver.
Solve Audio input-output not working problem with Realtek driver
First, you need to make sure it is a Realtek driver issue or anything else. so you go to the device manager to check this.
Right-click on My Computer icon and click on properties.
on the upper left corner, you will find the device manager option-click and open.
in the device manager, you need to find ( audio, video and game controller)
if you found it click to expand it then see if you find Realtek driver that means its installed in your pc.
How to check if the problem is in Realtek driver?
Now if you are in the device manager and already found the Realtek driver option in the given list.
then see on the Realtek driver option if an exclamation mark or any yellow icon is appearing with Realtek driver it means something is wrong with Realtek driver.
Now if you see an icon or mark on the Realtek driver it means you need to update your audio driver.
How to Update Realtek Driver?
The Update Process is quite easy and simple again goto device manager by following the above instructions.
right-click on the Realtek driver and you will see the option in the list for update driver. you can see it in the image given below.
if you want to get a complete and detailed post on how to update Realtek HD audio driver then you can follow this link and you will find the briefly described almost 3 ways to update your Realtek driver.