How to Fix Windows Security Not Working on Windows 11
Honestly, if you’re having trouble with Windows Security not running properly on Windows 11, you’re not alone. It’s more common than you might think. I ran into this myself after a couple of updates — sometimes, the Security Centre just… stops. The cause could be corrupted files, conflicting software, or missing updates. Here’s what finally worked for me, though it took a bit of trial and error — hopefully, this helps you fix it quicker.
Check for Windows Updates
This is my first go-to, because most issues stem from outdated components. To do this, press Windows + I to open Settings. Then, navigate to Windows Update. In older versions, I’d find it under Update & Security, but in Windows 11, it’s pretty straightforward.
Click Check for updates. If any are available, install them. Windows updates often include security patches, bug fixes, or vital components that might be causing your Security Centre to misbehave. Keep an eye out for optional updates or driver updates too — in my experience, those can sometimes resolve sneaky compatibility issues.
If your system is fully up to date and problems persist, it’s time to try some more advanced troubleshooting.
Run SFC and DISM to Repair System Files
This is where I started seeing real improvements, especially when system files or security components got corrupted. Open an elevated Command Prompt: press Windows + S, type cmd, right-click on Command Prompt, and select Run as administrator. PowerShell works too, but I prefer CMD for these repairs.
First, run:
sfc /scannowThis scans your Windows files and attempts to fix any issues it finds. Expect it to take a few minutes. Sometimes, it indicates it couldn’t repair all files, which is a sign to proceed with DISM.
Next, run these DISM commands in sequence:
dism /online /cleanup-image /checkhealth
dism /online /cleanup-image /scanhealth
dism /online /cleanup-image /restorehealthThis process can take some time, especially if your Windows image is badly corrupted; just be patient. It checks for deeper problems and repairs parts of Windows that SFC can’t touch. If you’re feeling cautious, you can specify a local source (like an ISO or installation media), but I only recommend that if nothing else works.
Once finished, restart your PC and see if Windows Security is functioning again. For me, running SFC and DISM often uncovered and fixed underlying issues that caused the security app to misbehave.
Reset or Reinstall Windows Security
If those steps didn’t do the trick, you can try resetting Windows Security directly. Head to Settings > Privacy & Security > Windows Security. Sometimes, there’s an option to Repair or Reset it from there — look for buttons or links. If those aren’t available or don’t work, resetting Windows altogether might be necessary.
To do that, go to Settings > Update & Security > Recovery and select Reset this PC. Be aware, this can be a bit of a hassle — it might remove your apps, but your files can often be kept if you choose “Keep my files”. It’s a bit of a nuclear option, but sometimes essential to fix deeply rooted problems.
Alternatively, you could try uninstalling and reinstalling just the Security app via PowerShell, but from experience, resetting the whole OS tends to be more reliable. Here’s a quick example if you’re curious (but only go this route if you’re comfortable with PowerShell and potential side effects):
Get-AppxPackage Microsoft.SecHealthUI -AllUsers | Remove-AppxPackage
# Reinstall from Microsoft Store or use deployment commands, but a full reset is usually simpler.Other Tips & Double Checks
In my experience, make sure that your TPM and Secure Boot are enabled — sometimes after updates or BIOS changes, these get disabled or show as greyed out. Check your BIOS/UEFI settings (usually by pressing Delete or F2 during startup) and look for options labelled TPM, Intel PTT, or AMD fTPM. Re-enabling them can resolve some security-related issues. Also, verify that the Windows Defender Antivirus Service is running: press Windows + R, type services.msc, and look for Windows Defender Antivirus Service. Its status should be Running and Startup type Automatic.
If issues persist, check the Event Viewer (Windows + R, type eventvwr.msc) — under Applications and Services Logs > Microsoft > Windows > Windows Defender, you might find specific error messages. Running a full scan with Malwarebytes or Windows Defender can also uncover malware or hidden problems interfering with security services.
All in all, it seemed like a bunch of small issues stacking up, but following these steps finally got my Windows Security working properly again. Troubleshooting can be a bit frustrating, but once everything’s sorted, it’s a relief to have that peace of mind.
Hope this helps — it took me ages to figure it out. Make sure BIOS settings are correct (TPM, Secure Boot), run SFC & DISM, and close apps that might conflict with security. Good luck, and always back up before major resets or BIOS tweaks. Persistence is often the key!