Windows significantly slower AFTER Cumulative Update for Windows 11 Version 23H2 for x64-based Systems (KB5037771)

Hi, Phil K. (CO)

Thank you for your response!

We understand that you you've had a clean install and are ready to purchase a new computer, and it looks like your situation will be alleviated in the future.

We're glad you're making such progress, and feel free to visit the Microsoft community again if you experience issues with Microsoft products in the future!

I wish you all the best!

Sincerely

Nicholas.Z - MSFT | Microsoft Community Support Specialist

Nicholas,

Thanks for this information. I attempted a Windows clean install multiple times - no significant improvement.

Here is a high-level view of what I did to address the performance issues after the update:

1. Create the Windows 11 iso usb drive
2. Create a Windows 11 Clean Install usb drive
3. Use tools available on reboot to... a. Remove/delete ssid drive partitions b. Reformat my ssid drive c. Install Windows 11 (using the clean install usb drive)

Note on using the usb drives - I needed to change my boot options in the bios to boot from the usb. My bios has a legacy boot option - but Windows 11 will give you an error message that your system requirements do not support Windows 11 - this is because the install requires a boot from using the UEFI boot option.

Boot to UEFI Mode or Legacy BIOS mode | Microsoft Learn

I did finally get a clean install. I am still in the process of re-installing my apps and getting the system to where I want it. When I've re-installed all my apps, I'll check the performance of each, and then, re-install my Norton 360 and Norton Utilities, and again check system performance.

Caution!

One last comment for anyone reading this reply - my solution may not work for you and if you choose to try something similar, be aware of the risks to your operating system and computer if you reformat your ssid drive. This was my last attempt to restore the performance of my system, and I was prepared to purchase a new pc in the event that after reformatting, the operating system or bios were no longer available. It took a lot of my time and perseverance to address the performance issues I experienced. My computer is an older Lenovo Flex 14. Specs are:

Processor Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz 1.99 GHz

Installed RAM 16.0 GB (15.9 GB usable)

System type 64-bit operating system, x64-based processor

Pen and touch Pen and touch support with 10 touch points

Hi, Phil K. (CO)

Welcome to Microsoft Community.

We understand that you are experiencing performance degradation after updating Windows 11 23H2, and after our testing, we have not found any related performance issues at 22631.3593 at this time. Based on your situation, this may be related to an error in a system component during the update, we suggest you try the following options:

1. Open PowerShell in administrator mode (Note: CMD does not work)
2. Execute the command: Set-ExecutionPolicy Unrestricted.
3. Execute the command: Get-AppxPackage Microsoft.SecHealthUI -AllUsers | Reset-AppxPackage
4. Go to Windows Defender, Device Security, Kernel Isolation, enable Memory Integrity, and reboot your system after enabling it for it to take effect.

If the above methods do not alleviate your lack of performance, it is recommended that you try the following options again:

ONE. Perform a clean boot

The method is as follows

1. Tap Windows+R and type msconfig
2. Open System Configuration and select General tab - Selective Startup.
3. Remove the checkbox of Load startup items.
4. Go to the Services tab - click Hide all microsoft services in the lower left corner, and then click Disable all.
5. Click OK and restart your computer. (Be sure to select Hide all Microsoft services first and then click Disable all, otherwise it may cause unforeseen problems such as not being able to access the system.)

See if the problem still recurs.

NOTE: Clean boot is a way to start Windows with a minimal set of drivers and startup programs so that you can determine if background programs are interfering with your games or programs and to help you figure out the cause of the problem. It will help you get back on track.

Disclaimer: A “clean boot” starts Windows with a minimal set of drivers and startup programs. It helps to determine whether a background service is interfering with your game or program and to isolate the cause of a problem.

These steps of "clean boot" might look complicated at first glance. However, to avoid any trouble for you, please follow them in order and step-by step so that it will help you get back on track. 

II. Try to repair your system

1. Search for CMD, find Command Prompt and select Run in Administrator Mode.
2. Enter the following commands one by one, be sure to execute the next command after the previous one is completed. DISM /Online /Cleanup-Image /ScanHealth DISM /Online /Cleanup-Image /CheckHealth DISM /Online /Cleanup-Image /RestoreHealth SFC /Scannow
3. After the scanning is completed, you can check the scanning information to see if the problem has been detected and fixed.

If the problem disappears during the above two steps, please try to remove the installed antivirus software/system optimization software/system monitoring software on your computer one by one until the problem disappears.

If the above two methods are still ineffective, we suggest you can try to repair your system by using Media Creation Tool in-place upgrade, which will refresh your Windows files and operating system without deleting files or applications. However, we still recommend backing up your computer in advance if it contains important data.

Once you have completed your backup, follow the steps in the guide below:

Download Media Creation Tool by visiting the site below and clicking on "Download Tool Now" (not "Update Now"). 

-Download Windows 11 (microsoft.com) Run the MCT tool, create an ISO image and run it!

When the ISO file has finished downloading, double-click it to open it and run setup.exe.

-Select "Not Now" on the "Get Updates, Drivers, and Options" page.

-Next Confirm your files, applications. Settings are preserved. It will also show you the version of Windows it will install.

If you are asked to enter a key, the ISO you downloaded does not match your current system version.

-On the Select what to keep screen, select Keep files and applications.

Click Install to begin the non-destructive repair

Disclaimer: Let’s try performing an in-place install or in-place upgrade which will refresh your Windows files and operating system without removing files or applications. That being said, we always recommend that if you have important data, you should back it up before making large system changes. If you want to back up your data first, please do so. Once you are done backing up, you can follow the steps in the following guides:

How to run In-place upgrade in Windows 11 - Microsoft Community 

Best Regards

Nicholas.Z| Microsoft Community Support Specialist