PC Model number?  Always include the model number on any initial problem post.

Can't give you model specific assistance, but many times Windows updates will mess up the sound driver and cause many sound problems.  First step is to reinstall the Dell sound driver for your specific model.

https://www.dell.com/support/home/en-us?l=en

Hi Nikital did you get this problem fixed. I have exactly the same problem, occurring after a Dell Support instigated update, not a windows update.

The Dell support have been very unhelpful.

I did manage to find a driver:

Intel(R) Smart Sound Technology (Intel(R) SST) OED

with a code 10 'Failed to load external libraries.'

This is likely related. I uninstalled it. It re-installed it on restart. Still microphone not found

I was using it all day the previous day

The Inspiron 5590 uses Realtek for PC sound.   The Intel sound is only for HDMI audio.

We have seen a lot of sound problems caused by Windows updates.  Reinstalling the model specific sound driver, Realtek for the 5590, cures the majority of problems.

Support for Inspiron 5590 | Drivers & Downloads | Dell US

I did manage to find a driver:

Intel(R) Smart Sound Technology (Intel(R) SST) OED

with a code 10 'Failed to load external libraries.'

This is likely related. I uninstalled it. It re-installed it on restart. Still microphone not found

Me to same problem any solution to this....

Seems to me we're having a run on disappearing microphone drivers!  In my case, a Inspiron 5491 2-in-1 laptop. This issue has cropped up since I last used the internal mic in a Zoom session about two weeks ago. Same discussion as elsewhere, does not show in the device manager to include viewing hidden devices.

I've updated the 5491 to current Dell patch levels.  This includes a BIOS update.  I've manually downloaded and re-installed the Realtek audio driver package.  Verified Windows 10 Home is current on patches. 

Still no microphone input device!

Any other ideas?

Mark

I have the same problem on an Inspiron 14 2-in-1.

Have you found a solution yet?

I am having the same problem and it is SO ANNOYING!  I just did an update and now no mic.  It's completely gone.  I tried to download the Realtek driver again and it didn't work.

Disclaimer: I just created my account and didn't even think until after I clicked submit that my username would look like I work for Dell - my bad. I don't. 

Anyways, I have the same issue. I just went to do a teleheath appointment and had to use my cellphone because my Inspiron 5491 2-in-1 can't find my microphone. . How has no one responded yet?

roll back to older Realtek driver as noted in this article https://www.dell.com/community/Vostro/No-input-devices-found-microphone/td-p/7879361