How to fix Windows 11 running slow after a major update

Summary

This guide helps you troubleshoot and resolve: How to fix Windows 11 running slow after a major update. Follow the steps below to fix the issue.

Common Causes

After installing a major Windows 11 feature update (such as 23H2 or 24H2) or a large cumulative update, it's common for your computer to feel sluggish for a short period. Windows often runs background tasks like indexing, driver optimisation, and Windows Update maintenance in the hours after an update, which can temporarily slow things down.

If your PC is still running slow after a day or two, the steps below will help you identify and resolve the cause. Work through them in order, testing your PC's performance after each one.

Quick Fix Steps

If you need a fast resolution, try these steps first:

1. Restart your computer — don't just shut the lid. A full restart clears stuck processes.
2. Wait 24 hours after the update, as Windows often performs background maintenance.
3. Check for further updates, as Microsoft frequently releases hotfixes shortly after major releases.
4. Run the Windows Update troubleshooter.
5. Disable startup programs you don't need.
6. Check Disk Space and run Disk Cleanup.
7. Run sfc /scannow and DISM to repair system files.

Detailed Instructions

1. Allow Windows to finish its post-update tasks

After a major update, Windows runs several background processes that can consume CPU, disk, and network resources for up to 24 hours. These include:

• Indexing files for search
• Optimising drives (TRIM/Defragmentation)
• Downloading and installing additional drivers
• Syncing OneDrive and Microsoft Store content

Open Task Manager (press Ctrl + Shift + Esc) and check the Processes tab. If you see Windows Update, Antimalware Service Executable, or Disk Cleanup using high resources, let them finish before troubleshooting further.

2. Install any pending updates

Microsoft regularly releases cumulative updates that fix performance issues introduced by earlier patches.

1. Open Settings (press Windows + I).
2. Go to Windows Update.
3. Click Check for updates.
4. Install everything available, including optional driver updates under Advanced options > Optional updates.
5. Restart when prompted.

3. Restart your computer properly

A full restart clears memory and stops background services that may be stuck after the update.

1. Click Start > Power > Restart.
2. Do not select Shut down, as Windows may apply pending updates on the next boot instead of clearing them.

4. Run the Windows Update Troubleshooter

1. Open Settings > System > Troubleshoot > Other troubleshooters.
2. Find Windows Update and click Run.
3. Apply any recommended fixes and restart.

5. Check your disk space

Windows 11 requires at least 20 GB of free space on the system drive to operate smoothly. Updates can leave behind temporary files that consume this space.

1. Open Settings > System > Storage.
2. Check the system drive (usually C:).
3. If free space is low, click Storage Sense and turn it on, or run Disk Cleanup manually:
   1. Press Windows + S, type Disk Cleanup, and press Enter.
   2. Select your system drive and click OK.
   3. Tick Windows Update Cleanup, Temporary files, and Delivery Optimisation Files.
   4. Click OK > Delete Files.

6. Disable unnecessary startup programs

Updates can reset some applications to launch at startup.

1. Open Task Manager (Ctrl + Shift + Esc).
2. Click the Startup apps tab.
3. Right-click any non-essential programs (such as chat clients, cloud sync tools, or game launchers) and select Disable.
4. Restart your computer.

7. Repair system files

Corrupted system files can cause slowdowns after an update. Use the built-in System File Checker and DISM tools.

1. Click Start, type cmd, right-click Command Prompt, and select Run as administrator.
2. Type the following commands, pressing Enter after each:
   DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow
3. Wait for both to complete. This can take 20–30 minutes.
4. Restart your computer.

8. Roll back or uninstall the update

If performance has only been poor since a specific update, you can remove it.

1. Open Settings > Windows Update > Update history.
2. Click Uninstall updates.
3. Find the most recent update, click Uninstall, and follow the prompts.

For feature updates installed more than 10 days ago, you can perform an in-place repair using the Microsoft Media Creation Tool. This reinstalls Windows 11 without removing your files or applications.

9. Check for driver issues

Major Windows updates often install generic drivers that may not perform as well as the manufacturer's versions.

1. Open Settings > Windows Update > Advanced options > Optional updates.
2. Expand Driver updates and install any available updates.
3. If your device manufacturer (such as Dell, HP, or Lenovo) provides its own driver package, visit their support site and install the latest versions for your model.

Troubleshooting

Boot times are much longer than usual

If your PC takes a long time to reach the desktop after the update, check whether Fast Startup is enabled:

1. Open Control Panel > Power Options > Choose what the power buttons do.
2. Click Change settings currently unavailable.
3. Tick Turn on fast startup (recommended) and click Save changes.

If boot times are still slow, run msconfig from the Start menu, open the Services tab, tick Hide all Microsoft services, and disable any third-party services you don't need.

High disk or CPU usage after the update

Open Task Manager and sort by Disk or CPU. Common culprits include:

• SysMain (Superfetch) — Right-click in Task Manager and select Disable if you have an SSD.
• SearchUI.exe or SearchHost.exe — These can spike during indexing. Let them finish or restart Windows Search via net stop wsearch followed by net start wsearch in an elevated Command Prompt.
• Antimalware Service Executable — Indicates Windows Security is scanning. Allow it to complete.
• Windows Update — Indicates updates are still installing in the background.

If a specific process consistently uses high resources for more than 24 hours, search for the process name on Microsoft's support site or your device manufacturer's support page for known issues.

Apps are slow to open or freeze

If specific applications are slow after the update:

1. Open Settings > Apps > Installed apps.
2. Find the affected app, click the three dots, and select Modify or Repair if available.
3. If repair isn't available, select Uninstall, then reinstall the latest version from the developer's website.

Check the software developer's website for compatibility notes regarding the latest Windows 11 update.

System feels slow even after all steps

If performance issues persist after completing all the steps above, consider performing an in-place repair install using the Media Creation Tool. This reinstalls Windows 11 while keeping your files and most applications intact, and often resolves deep-seated update-related issues.

Before doing so, back up important files and note any application licences or product keys you may need to reactivate afterwards.

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