Windows 11 Home is too slow (Disk usage always at 100%, CPU also high)

Question

Windows 11 Home is too slow (Disk usage always at 100%, CPU also high)

Rob H 0

I have a Desktop with a 2.9 GHz processor and 8GB of Ram, so well above the minimum specs for Windows 11. My computer has gradually been getting slower with each windows update (computer started on Windows 10), to the point where after an enforced Microsoft update at the start of September, Windows now runs so slowly that it is basically unusable. Takes 20mins to log on. Disk usages is constantly at 100% so few programs can run.

After trying the usual solutions I used the boot menu to 'reset Windows'. This means that I basically have a fresh install of Windows 11 on my machine, but it hasn't solved the problem. The computer is very slow and I can't even get on the internet because Microsoft Edge crashes whenever loading (prior to the reset I could get on the internet with Pale Moon, but that's now been uninstalled due to the reset).

After searching for solutions I have done the following

Uninstalled McAfee Antivirus scanner, One Drive and Co Pilot (these were apps that came automatically with the reset windows update but seem to use a lot of space and/or processing)
Turned off all app notifications
Removed some programs from Start up
Disabled visual telemetry and Windows Search (Connected user experience / sys main) from services
Ensured drivers and storage controllers were up-to-date from Device manager
Turned off automatic drive optimisation
Manually ran the optimisation and defragmentation.

None of these changes have sped up the machine. When I go into task manager there is always a variety of Windows processes that are hogging all the disk usage. If I try to turn them off, I am either prevented from doing this, or they do stop and another Windows process takes its place. After all the above actions, and even with no programs running. the processes that seem to regularly be using the majority of the RAM are (note usages changes over time, but these seem to be the main offenders):

System: MsMPEng.exe
MsEdgeWebView
Service Host: Crytographic services
Service Host: Delivery Optimisation
Windows Widgets
Microsoft Office Click to run (note - do not have Mircosoft Office installed on machine).

I've copied all the file contents onto a (much lower spec) laptop running Ubuntu, and that works fine, so there's nothing in my file system which is causing this slow down. There is no 3rd party software on the machine, so this is entirely an issue with Windows. I'm pretty much at the point now where I think I should just uninstall windows and run a Linux operating system on the machine instead. Is there anything else I can do to get Windows to work?

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5 answers

Your answer

Answer 1

Igor Leyko 112.4K Independent Advisor

Seems the problem is caused by Microsoft Offive installation. Try to repair Office installation. What exactly Office version do you have?

Rob H 0 Reputation points

2026-10-06T20:06:01.8533333+00:00

Thanks for your reply. Running Win11 Home 25H2 26200.8655. A full reinstall of windows via the Reset my PC option was performed on 22nd Sept and didn't improve performance. I tried repairing the previous Windows installation before that and that didn't do any good either. In response to your suggestion I have now tried to repair the 'Microsoft 365' app (there is no Office app) both using the 'quick repair' and the 'online repair'. Both seemed to run OK, but neither helped with the disk usage/speed of windows.

Answer 2

Old observer 240 Volunteer Moderator

Drive is in good physical condition.

Please run Task manager, go to Performance tab, select Disk C:, and show a screenshot with high disk load.

Check if the problem exists during clean boot. https://support.microsoft.com/topic/how-to-perform-a-clean-boot-in-windows-da2f9573-6eec-00ad-2f8a-a97a1807f3dd

Rob H 0 Reputation points

2026-10-04T09:14:25.1+00:00

Thanks for your reply. The problem continues after the clean boot (I don't have any third party software on the machine since I reset it, so disabling non-microsoft processes unlikely to help). I've attached Screenshots of the Performance and Processes tab of the Task Manager, from both before and after the clean boot.

The start up processes I disabled were SKIFundKB, SecurityHealthSysTray and RiskandUSerwise64 - these were the only 3 that were unable. I'll leaving the services/startup apps disabled for now.
Rob H 0 Reputation points

2026-10-04T09:18:21.2+00:00

Thanks for your reply. The problem continues after the clean boot (I don't have any third party software on the machine since I reset it, so disabling non-microsoft processes unlikely to help). I've attached Screenshots of the Performance and Processes tab of the Task Manager, from both before and after the clean boot.

The start up processes I disabled were SKIFundKB, SecurityHealthSysTray and RiskandUSerwise64 - these were the only 3 that were unable. I'll leaving the services/startup apps disabled for now.
Rob H 0 Reputation points

2026-10-04T09:25:40.35+00:00

Hi. Can you confirm that my replies to this comment have appeared? I posted the screen shots but this site is so buggy that I think I double posted because the site appeared to crash on first attempt. When I log back on the comments don't show unless I press refresh, when two identical comments show.I also have to transfer the files to my Linux machine to post anything because Ignite won't accept the comments if I try to post them from my Windows machine. I also can't log onto the my Microsoft Hotmail account with Microsoft Edge (have to use Pale Moon instead) because with Edge it erroneously reports 'multiple failed log on attempts' - this is a common problem apparently - seems like everything Microsoft produces now is full of bugs!!!!

Answer 3

Update - I tried the AI answers suggestions:

Option was not available
Not relevant
Already tried
Not relevant (plenty of spare disk space)
Got message saying: Restorehealth option unknown. I ran the scannow code anyway but didn't seem to find anything (reported 'No integrity violations')
Not relevant
Already tried
Already tried
This seemed to make the computer a bit quicker, but disk was still showing consistently at 100%

I have found a temporary solution - increasing the virtual memory allocation through System>View Advanced System Settings>Advanced>Performance>Settings>Advanced>Virtual Memory>Change. I changed the max to 24576 (from the recommended of 1875) and the computer is now just about useable, if still very slow. Disk now shows as around 70% in task manager.

I'll try the CrystalDiskInfo next time I log on if I can download it (above checks took 2.5 hours, given speed of system).

Answer 4

Old observer 240 Volunteer Moderator

Please check drive's health with third-party CrystalDiskInfo tool and show its window.

Rob H 0 Reputation points

2026-09-29T18:58:42.11+00:00

This is the output from Crystal Disk. It reports the drive as being 'Good'

Answer 5

Given the reset did not help, focus on Windows repair and update troubleshooting rather than more app removals.

Set the device to a higher performance power mode.
- Go to Start > Settings > System > Power & battery.
- For Power mode, select Better performance or Best performance.
Check Surface-specific steps only if this is a Surface device.
- Open the Surface app and expand Help & support.
- If updates are available, select Check for updates.
Restart the PC.
- Go to Start > Power > Restart.
Free up drive space if the system drive is close to full.
- Windows updates can require significant free space.
- Go to Start > Settings > Windows Update and select Check for updates after space is available.
Run Windows image and system file repair.
- Warning: these steps require administrator permissions and command-line use.
- In the taskbar search box, type command prompt, then select Run as administrator.
- Run:
```
     DISM.exe /Online /Cleanup-image /Restorehealth
```
- Wait for the confirmation that the operation completed successfully.
- Then run:
```
     sfc /scannow
```
- Wait until verification reaches 100%, close Command Prompt, then try Windows Update again.
If Windows Update is failing or stuck, reset the update components.
- Warning: these steps require administrator permissions and command-line use.
- Open Command Prompt as administrator and run these commands one at a time:
```
     net stop bits
     net stop wuauserv
     ren %systemroot%\softwaredistribution softwaredistribution.bak
     ren %systemroot%\system32\catroot2 catroot2.bak
     net start bits
     net start wuauserv
```
- Restart the computer after the commands complete.
Check for software conflicts.
- Perform a clean restart into Windows to start with a minimal set of drivers and startup programs.
- This helps identify whether background software is contributing to the high disk usage.
Temporarily remove third-party security software if any remains.
- Third-party antivirus can interfere with updates.
- Before uninstalling, make sure reinstall steps and any product keys are available.
Check the drive for file system errors.
- Warning: this requires administrator permissions and a restart.
- Open Command Prompt as administrator and run:
```
     chkdsk /f C:
```
- Restart when prompted so repairs can run.
If the PC still remains unusably slow after the repair steps, use the clean installation option for Windows 11 from the software download page.
- Read the notes on that page carefully before using the tool.

The most relevant next steps for this case are DISM, SFC, resetting Windows Update components, CHKDSK, and a clean restart. Those are the supported repair paths when a reset has not resolved persistent Windows slowness and update-related corruption.

References: