According to users, after installing Tuesday's update of Microsoft's April 2019 patch this week, Windows has suddenly become slow and programs have taken a long time to open.
Yesterday, we reported a conflict between the latest Windows updates and Sophos, Avast, and Avira antivirus software, which caused Windows to hang or to stop updates.
Since then, we've received emails and seen user reports claiming that this week's updates also slowed down Windows. The reports we saw came from users running Windows 7 and Windows 10.
Some of the issues faced by users include Windows startup or restart, unable to start programs, shifting gaming, excessive disk activity, video streaming issues, and other issues. similar problems.
For example, in a comment on BleepingComputer, a reader stated that his Windows 10 computer has become extremely slow and that restarting / starting Windows takes forever.
Users on Reddit [1, 2, 3, 4, 5, 6] and elsewhere [1,2] also complain that Windows has become very slow since the installation of the updates.
Although I was not able to verify it on my own Windows 10 computer, a Reddit user said that the problems were caused by Windows Defender.
Normally, when a user has an antivirus program, Windows Defender disables its protection in real time. It seems at least for this user that Windows Defender is activated automatically even if the user had installed Avira on the machine.
Having two antivirus programs providing real-time protection can definitely cause slowdowns and other problems.
To date, nothing in Microsoft indicates that they are aware of the issues reported. The only reference to the slow Windows since the updates comes from a support article published yesterday by Avira and titled simply "Why is my system very slow?".
This article states that if Windows 10 has become slow, you must remove the update KB4493509. For Windows 7 users, they indicate that you must remove the updates KB4493472 and KB4493448 for Windows 7.
Because these instructions are for users of their software, they may not apply to everyone.
BleepingComputer has contacted Microsoft to find out if they are aware of these issues but have not received a response to date.
Note that I personally have no problem after installing these updates for Windows 10 and running ESET Nod32. If you have problems, can you please leave a comment and let us know if Windows Defender is enabled with your audiovisual software or anything else you have tried to resolve.
Updated: 12/04/19 18:54 EST: Woody Leonhard also reported on Computerworld that he was seeing slowing problems under Windows 10 after installing these updates.