Microsoft recently released the Patch Tuesday update KB4549951 (Builds 18363.778 and 18362.778) for Windows 10 version 1903/1909. Now not only many users are reporting that this update fails to install, but few other users who installed it are even facing serious issues like deletion of files from C drive, disabling of microphones, camera & USB ports, defender shutting down and many other issues like slow performance.

Users have reported the update KB4549951 failing to install with errors 0x800f0985, 0x800f0900, 0x80073712 and more.

Unable to install KB4549951
Hello! I have attempted multiple avenues of installing the latest update to Windows 10 but have not had any success.  I get the following error code 0x80073712, and reviewing the troubleshooting information including running the Windows Update Troubleshooter and the DISM tool.  The DISM Tool came back with this response:  Error: 0x800f081f

Users also reported about the update disabling USB ports, microphones, and even the camera.

USB ports not working after update April 14, 2020—KB4549951
None of my usb ports or devices show up after the update April 14, 2020—KB4549951. I’ve verified this by rolling out the update – all devices and drives work – install it and none show up.

I’ve turned off updates for the time being but I’d like to fix this issue I can only stall the update off for so long and have NO idea how to fix this mess.

Thanks for any help.

A user has reported about the update deleting files in his C Drive.

Microsoft Update KB4549951 deleted my files! HELP!
Logged on to my computer this morning and saw that an auto update installed.  Had not had my coffee yet and it said something about temp access.  I freaked out!!   I think I was able to find most of my files and copy to external drive.   Then per instruction I restarted my computer.  My files are ALL GONE FROM C DRIVE!!

In looking around for info on how to fix found something about uninstalling update when this happened to others on a different update.  Not sure if I should try this?    Maybe hope that the files I copied before re-start are not screwed up.

What do I do?

One user reported about the internet speed being severely affected after the installation of the update.

KB4549951 causing issues
Ever since KB4549951 was installed on my Win 10, my internet speed has slowed to a crawl.

It even causes programs to freeze

I am about ready to remove it. What’s the story?

Some users reported about the Defender not working and shutting down after installing the update KB4549951.

Windows Defender shuts down
For some reason, yesterday and again today, Defender has turned OFF for no reason and I can’t get it restarted without a restart. Then it will seem to start normally only to shut down shortly thereafter. The only change to my PC was been a Windows auto update KB4549951

Microsoft needs to fix these issues for restoring user confidence before it plans to launch the next major Windows 10 feature update “May 2020 update” to users.