Users are reporting that after installing this week’s Microsoft’s April 2019 Patch Tuesday updates, Windows has suddenly become slow and programs are taking forever to open.
Yesterday, we reported that there is a conflict between the latest Windows updates and Sophos, Avast, and Avira antivirus software that is causing Windows to freeze or updates to not finish installing.
Since then, we have received emails and seen reports from users who have stated that this week’s updates are also causing Windows to become very slow. The reports we have seen have been from users running Windows 7 and Windows 10.
The issues that users are experiencing include Windows taking a long time to start or reboot, unable to start programs, lag in games, excessive disk activity, video streaming issues, and other similar problems.
For example, in a comment at BleepingComputer a reader has stated that their Windows 10 computer has become extremely slow and that rebooting/starting Windows takes forever.
While I have not been able to verify this on my own Windows 10 computer, one user on Reddit stated that the issues were being caused by Windows Defender.
Normally when a user has an antivirus program, Windows defender will disable its real time protection. It seem for this user at least, Windows Defender is being enabled automatically even though the user had Avira installed on the machine.
Having two antivirus programs performing real-time protection could definitely cause slowdowns and other issues.
At this time there is nothing from Microsoft that states they are aware of the reported issues. The only reference to Windows being slow since the updates is from a support article posted yesterday by Avira that is simply titled “Why does my system run very slow?“.
As these instructions are for users of their software, it may not apply to everyone.
BleepingComputer has contacted Microsoft to see if they are aware of these issues, but have not heard back as of yet.
It should be noted that I personally have no issues after installing these updates for Windows 10 and running ESET Nod32. If you are having issues, can you please leave a comment and let us know if Windows Defender is enabled along with your AV software or other things you have tried to resolve the issue.
Update: 4/12/19 6:54 PM EST: Woody Leonhard also reported on Computerworld that he is seeing users have slowdown issues on Windows 10 after installing these updates.