Windows 11 includes Microsoft Defender Antivirus through the Windows Security app. You can run a quick scan for a fast check, or choose a more thorough scan when you have a reason to suspect unwanted software.
Run a Quick Scan
- Open Windows Security from the Start menu or search.
- Select Virus & threat protection.
- Select Quick scan.
- Wait for the scan to finish and review the results.
Run a Full Scan
- Open Windows Security > Virus & threat protection.
- Select Scan options.
- Choose Full scan.
- Select Scan now and allow the scan to complete.
Use a Custom Scan
A custom scan can check a particular file or folder when you do not need to scan the entire PC. Open Scan options, choose Custom scan, and select the location you want to examine.
Use Microsoft Defender Offline
If you suspect persistent malware that may interfere with Windows while it is running, Microsoft Defender Offline can restart the PC and scan outside the normal Windows environment. Save your work first and follow the Windows Security prompts.
Review Protection Status
A clean scan is useful evidence, but no antivirus scan can guarantee that a computer is free of every possible threat. Keep Windows and security intelligence updated, install software from trusted sources, and investigate recurring warnings rather than repeatedly dismissing them.
Summary
Use Windows Security to run Quick, Full, Custom, or Offline scans as appropriate. Keep Defender updated and treat a clean result as one part of a broader security strategy.