How to Fix Windows Security Not Working on Windows 11
Honestly, if you’re struggling with Windows Security not functioning properly on Windows 11, it’s more common than you’d think. This happened to me after a couple of updates—sometimes, the Security Center just… stops. It might be due to corrupted files, conflicting software, or even missing updates. So, here’s what finally worked for me, though it took some trial and error—hope it helps you get it fixed faster.
Check for Windows Updates
This is the first step I always try, because lots of issues are caused by outdated components. To do this, press Windows + I to open Settings. Then, go to Windows Update. For some reason, on older builds, I’d find it under Update & Security, but in Windows 11, it’s pretty straightforward.
Click Check for updates. If your system finds anything, install it. Windows updates often include security patches, bug fixes, or critical components that might be causing your security center to act up. Keep an eye out for optional updates or driver patches too—in my experience, those can sometimes fix sneaky incompatibilities.
If your system’s already fully updated, and you’re still having issues, it’s time to move to more advanced troubleshooting.
Run SFC and DISM to Repair System Files
This is where I started running into some real fixes, especially when system files or security components got corrupted. You need an elevated Command Prompt: press Windows + S, type cmd, then right-click Command Prompt and choose Run as administrator. PowerShell works too, but I prefer CMD for these repairs.
First, run:
sfc /scannowThis scans your Windows files and tries to fix whatever’s broken. Expect it to take a few minutes. Sometimes, it reports that it couldn’t fix all files, which is a sign to move on to DISM.
Next, run these DISM commands one after the other:
dism /online /cleanup-image /checkhealth
dism /online /cleanup-image /scanhealth
dism /online /cleanup-image /restorehealthThis process can take quite a bit of time, especially if your image is really hosed; just be patient. It checks for deeper corruption and repairs parts of Windows that SFC might not touch. Sometimes, if you’re feeling extra cautious, you can point /Source to a Windows install media or ISO, but I only go there if nothing else works.
After all of that, reboot your PC and see if Windows Security is back up. Usually, running SFC and DISM did the trick for me in fixing underlying issues that caused the security app to malfunction.
Reset or Reinstall Windows Security
If those steps didn’t solve the problem, you can try resetting Windows Security directly. Head into Settings > Privacy & security > Windows Security. Sometimes, there’s an option to Repair or Reset it there—look for a button or link. If that doesn’t work, or those options aren’t available, then resetting Windows entirely might be needed.
To do that, go to Settings > Update & Security > Recovery and choose Reset this PC. Keep in mind, it can be a hassle—it’ll probably remove your apps, but you generally get to keep your files if you pick “Keep my files”. It’s a bit of a nuclear option, but sometimes that’s what it takes to fix deeply rooted issues.
Alternatively, you might try uninstalling/reinstalling just the Security app via PowerShell commands, but honestly, I found that resetting the whole OS was more reliable. Here’s a quick example if you’re curious, but don’t go that route unless 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 resetting is usually simpler.Other Tips & Things to Double-Check
In my experience, make sure that your TPM and Secure Boot are enabled—sometimes after updates or BIOS changes, they get disabled or show grayed out. Check in your BIOS/UEFI setup (usually by pressing Delete or F2 during startup) and look for options labeled like TPM, Intel PTT, or AMD fTPM. Turning them back on can fix some security-related issues. Also, verify that your Windows Defender Antivirus Service is running: press Windows + R, type services.msc, and find Windows Defender Antivirus Service. Its status should be Running and Startup type Automatic.
If after all this the security tools are still acting weird, look into Event Viewer (Windows + R, type eventvwr.msc)—check under Applications and Services Logs > Microsoft > Windows > Windows Defender for specific errors. Running a Malwarebytes or Windows Defender full scan might uncover hidden issues or malware that could interfere with security services.
It really felt like a jumble of small issues that added up, but combining these steps finally got my Windows Security working properly again. It’s frustrating to troubleshoot, but once everything’s fixed, it’s so good to have that peace of mind again.
Hope this helped — it took me way too long to figure it out. Double-check that everything in your BIOS is enabled (TPM, Secure Boot), you’ve run SFC & DISM, and you’ve closed out background apps that might conflict with security. Good luck, and don’t forget to make backups before doing major resets or BIOS changes. Sometimes, persistence is the only way!