The latest Windows Update is causing a range of problems:

“KB 3004394 blocks the installation or update of graphics drivers such as AMD’s new Catalyst Omega. Nvidia users are also reporting difficulty installing GeForce drivers.” – Jason Evangelho

It has been recommended to remove it manually. and MS agrees.

What other problems does it cause?

“USB 3.0 drivers are broken and User Account Control (UAC) prompts have gone haywire. Microsoft has acknowledged that it even prevents the installation of future Windows Updates.

Perhaps most troubling is that the Windows Defender service – crucial software that blocks viruses and malware — has been disabled by the update.” –ibid

MS has already issued a patch for this patch. Sheesh. It’s KB3024777. You might well have been fixed already.

If not: To remove KB3004394, go to Control Panel -> Windows Update -> View Update History -> Installed Updates. Then, highlight the update named KB3004394 and click the “Uninstall” button.

This is confirmed to resolve the issues, and Microsoft has removed the original update from Windows Update.

“The moral of the story is this: Return to your main Windows Update area and change your settings from “Install updates automatically” to “Check for updates but let me choose whether to download and install them.”- ibid

I’d suggest just one modification of that: If there are “Critical Updates”, especially of the RCE variety (remote code execution) and/or “Zero Day” patches or fixes, install them immediately. Remember, Evangelho is talking about “System patches”, NOT “Security patches”.