General slowdown after upgrading to MacOS 26.0.1

There are two very different procedures to get the machine back to the way it should be working 

1 - Uninstall Kaspersky in its entirety via the Developers Specific Instructions 

Run the Etrecheck Report a second time and post a new report 

Just to check if every bid of Kaspersky has been remove 

If all goes well and we hope so

Restart the M2 Mac Mini is Recovery Mode  and choose the Reinstall  macOS 

This will not touch your setting, files and preferences 

It will Install Over the Existing Operating System, replacing any corrupted, missing or other wise modifies file 

Cross your finders this will work and put the machine back on track

The Other Procedure that is not popular but more effective 

Once this type of software are installed and embedded into the computer Kaspersky

Start Over from Scratch 

Heavy Handed ? - Yes

Effective in removing the AV Software ? - Yes 

You can spend hours or days hunting down all the bits and pieces of this software and never really get it all off the computer

For Apple Silicon computer >> Use Disk Utility to erase a Mac with Apple silicon.

Always make a Time Machine Backup  before  proceeding 

Emphasis on User Account Only

If going this route - I suggest Not using Startup Assist to migrate everything back.

This will probably Re-Introduce (Kaspersky Internet Security) back into the Operating System . 

Q - Antivirus software: Apple and Kaspersky

System Extensions:

    [Running] Kaspersky System Extension - version 26.0.0.94 (Kaspersky Lab Switzerland GmbH - installed 2025-09-12)

        Application: /Applications/Kaspersky Anti-Virus For Mac.app - version 26.0.0.94 (Kaspersky Lab Switzerland GmbH - installed 2025-09-12)

        Description: Kaspersky System Extension monitors real-time file activity, processes attempting to run and network activity to protect user from malicious web resources and network attacks

Q - [Running] com.kaspersky.kav.kavd.plist (Kaspersky Lab Switzerland GmbH - installed 2025-09-12)

        Command: /Applications/Kaspersky Anti-Virus For Mac.app/Contents/MacOS/kavd.app/Contents/MacOS/kavd -r -bl

 Q - [Not Loaded] com.piriform.ccleaner.engine.xpc.plist (Piriform Ltd - installed 2024-08-25)

       Executable: /Applications/CCleaner.app/Contents/Frameworks/CleaningEngine.framework/XPCServices/com.piriform.ccleaner.engine.xpc

 Q -  [Not Loaded] com.google.keystone.agent.plist (Not signed - installed 2025-06-01)

Q - [Loaded] Kaspersky Password Manager Login Item (App Store - installed 2025-09-19)

        Modern Login Item

        /Applications/Kaspersky Password Manager For Mac.app/Contents/Library/LoginItems/Kaspersky Password Manager Login Item.app

Q - [Not Loaded] Kaspersky Secure Connection Login Item (App Store - installed 2025-07-13)

        Modern Login Item

        /Applications/Kaspersky Secure Connection.app/Contents/Library/LoginItems/Kaspersky Secure Connection Login Item.app

Q -  VPNs:

        [Loaded] KSECNetworkExtension - /Applications/Kaspersky Secure Connection.app

cenk225 wrote:

Hello,

It's been about a month since I did the update. After the upgrade, my computer has been running slower overall. Especially when I go into System Settings, the icons take a long time to appear. This is very annoying. My computer is a Mac mini M2 with 16GB of RAM and 512GB of storage.

Part 1 of 2

Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal.

Safe Mode will also eliminate Third Party Software, extensions and drivers from loading. It will only load the Minimum amount of Core Apple Processes to allow the the computer to function at a reduced Level of Performance 

Does the issue present in this mode ?

Sometimes a Safe Boot followed by a Normal Boot will just put things right.

If not - there could be something in the main User Account playing up. To further isolate this - Set up users, guests, and groups on Mac. Then log out of the Main User account and log into the dummy account and test again if the issue persists.

If the issue is present in the dummy account - then, this appears to be a System Wide issue on the computer.

Part 2 of 2

To Drill Down further and to avoid a session of Q&A, Q&A  and Q&A  

Download the Application Etrecheck  ( External Link ) directly from the Developer.

The Application is Not a " Silver Bullet "  and is  only a tool to examine the Hardware / Software used on this computer 

This is a Diagnostic Tool that makes no changes to the computer Hardware / Software used on this computer 

The application is free or paid from added features. 

The Report will Not Reveal Any Personal Information. 

Post back the Full Report - copy and paste - >>>> using the Additional Text Icon ( 3rd Icon to last ) <<<<

Common issues that will impact the overall performance

Third Party 2 Way Firewalls 

Commercial VPNs 

Third Party Security Software 

Third Party Disk Cleaners / Optimizer 

Lack of Free Space

It is possible there are processes running in the background that are using significant resources. Check Activity Monitor, CPU tab, sort by % CPU to see what's running hard.

Activity Monitor User Guide for Mac - Apple Support

Go_West wrote:

I noticed that resizing windows is laggy in Tahoe. Incredible

Same answers, check Activity Monitor, try Safe Mode. It’s laggy because of something you have installed that is not fully compatible with Tahoe. Tahoe itself is fine.

Contact the 3rd party developer about updates for Tahoe compatibility.

In general, apps that purport to ‘clean’, ‘optimize’ or ‘protect’ your Mac are not only unnecessary they are often problematic as you’re finding out. My recommendation would be to uninstall all such apps using the developer’s uninstaller.

Go_West wrote:

I noticed that resizing windows is laggy in Tahoe. Incredible

To get better and individualize support / advise that is specific to your computer

Suggest you open your Own question

Piggy-backing on an existing question will often get lost or not answered

Thank you for the additional informations

Skip the First Part of my reply and jump Directly to Etrecheck

Then, Post the Full Report as per instructions

I noticed that resizing windows is laggy in Tahoe. Incredible

Thank you 👍

We do see the report and will get back to you