How To Perform a Complete System Scan on Windows 11 for Optimal Security

Running a full system scan on Windows 11 is kind of like giving your PC a deep health check. You open the Windows Security app, click around to the “Virus & threat protection” section, and then hunt for “Scan options.” When you pick “Full scan” and tap “Scan now,” your computer starts a thorough sweep—checking every single corner, nook, and cranny for harmful stuff. Not gonna lie, it can take a while, especially if you’ve got a ton of files, so patience is a virtue here. Sometimes, it feels like it’s never gonna finish, but in the end, peace of mind is totally worth the wait.

Note: On some setups, this process weirdly stalls on the first try, then runs smoothly after a quick reboot. Probably Windows being Windows. So if it seems stuck, give it a restart and try again.

Here’s how to do it step-by-step:

Method 1: Using Windows Security GUI

1. Open Windows Security: Click the Start button, type Windows Security in the search bar, and hit Enter.
2. Go to Virus & threat protection: Once the app opens, find and select Virus & threat protection from the left menu.
3. Click on Scan options: In the section labeled “Current threats,” find and tap Scan options.
4. Select Full scan: Among the options, choose Full scan. It’s the most thorough—covers everything.
5. Start scanning: Hit Scan now. Sit back and let it do its thing. Expect it to take quite a bit of time—possibly over an hour if your drive is huge—and don’t use your PC too heavily while it runs.

   Method 2: Using Command Prompt (Advanced, but sometimes faster)

   1. Open Command Prompt as administrator: Press Windows key + R, type cmd, then hit Ctrl + Shift + Enter to run as admin. Confirm any prompts.
   2. Run a full scan with Windows Defender CLI: type mpcmdrun -Scan -ScanType 2 and press Enter.
   3. This command kicks off a full system malware scan. It’s invisible but runs in the background. Check the progress in the Security app or Event Viewer if needed.

      Why it helps: Using the command line can sometimes bypass UI glitches, especially on slower systems or after minor updates. Plus, it’s straightforward once you get the hang of the commands. When should you do that? Usually when GUI seems frozen or you want a quick scriptable way to run scans.

      When to use these methods:
      – You’re suspecting malware but don’t want to mess around with third-party tools.
      – System feels sluggish, or you’re seeing strange pop-ups or crashes.
      – Regular maintenance setup—schedule this through Windows Security to keep things in check.

      Expect to get a notification about found threats, and then you can choose to quarantine or remove them. Sometimes, Windows reports false positives, so don’t panic if it flags some files you recognize. Just double-check before deleting.

      If that didn’t help, here’s what might: the scan could get stuck due to corrupted system files or conflicting software. Running in Safe Mode can help, or even resetting Windows Security settings. When all else fails, running a maintenance tool like SFC /scannow or DISM /Online /Cleanup-Image /RestoreHealth in PowerShell might clear out underlying issues.

      Hopefully, this shaves off a few hours for someone. Good luck keeping your machine clean!

      Tips for Running a Full System Scan on Windows 11

      • Make sure your device is plugged in if you’re on a laptop—no one wants unexpected shutdowns mid-scan.
      • Close any apps you don’t need — especially if they’re heavy or consume a lot of resources. The scan will thank you.
      • Set up scheduled scans in Windows Security’s Virus & threat protection settings. Automate it and have less to think about later.
      • Update your virus definitions first — there’s a little toggle for that in the same app, usually under Check for updates.
      • If malware seems persistent, consider booting into Safe Mode (Shift + Restart and select “Troubleshoot” > “Advanced options” > “Startup Settings” > “Restart”, then pick Safe Mode). It’s a lot better for tricky infections.

      Frequently Asked Questions

      How long does a full system scan take on Windows 11?

      Expect anywhere from 30 minutes to a few hours. It depends on how much data you got and how fast your drive is. If you got an SSD, it’s quicker. Spinning rust? Prepare for a wait.

      Can I use my computer while the scan runs?

      Sure, but it’s a bad idea if you want a thorough check. Your PC will slow down, and the scan might take longer. Better to set it running overnight or when you’re not gonna need it.

      Do I need third-party antivirus on Windows 11?

      Not necessarily—Windows Security is pretty decent out of the box. But if you want extra features or layered protection, third-party options aren’t a bad idea.

      What if it finds something?

      Follow the prompts—quarantine or remove. Sometimes, it’s false alarms, so double-check files if you’re unsure. Better safe than sorry.

      Can scans be scheduled automatically?

      Absolutely. In Windows Security, go to Virus & threat protection > Manage settings > Scheduled scans (or similar), and set how often you want.

      Summary

      • Open Windows Security.
      • Head to Virus & threat protection.
      • Pick Scan options.
      • Choose Full scan.
      • Hit Start & wait.

      Worked for me — hope it works for you.