Setting up Windows Defender: Get the most out of your built-in security

Windows Defender, officially called Microsoft Defender Antivirus, is the free antivirus solution built into Windows 10 and 11 by default. What was once a basic solution is now a full-fledged security program that scores excellently in independent tests. In this guide you'll learn how to set up Windows Defender optimally for the best protection.

Opening Windows Defender

There are several ways to get to the Windows Defender settings.

Via the Start menu

  1. Click the Start button
  2. Type Windows Security
  3. Click Windows Security in the results

Via Settings

  1. Press Windows + I to open Settings
  2. Click Privacy & security (Windows 11) or Update & Security (Windows 10)
  3. Click Windows Security
  4. Click Open Windows Security

Via the system tray

You'll see a small shield icon at the bottom right of the taskbar, next to the clock. Click it for quick access to Windows Security.

Understanding the security dashboard

When you open Windows Security, you see the main dashboard with several protection areas:

  • Virus & threat protection: Your main antivirus protection
  • Account protection: Protection for your Windows account
  • Firewall & network protection: Network security
  • App & browser control: Protection against harmful downloads and websites
  • Device security: Hardware-based security
  • Device performance & health: The health of your system
  • Family options: Parental controls

A green check mark means everything is in order. A yellow exclamation mark needs your attention, and a red cross means action is required.

Setting up Virus & threat protection

This is the heart of Windows Defender. This is where you configure the antivirus features.

Checking real-time protection

  1. Open Windows Security
  2. Click Virus & threat protection
  3. Click Manage settings under Virus & threat protection settings
  4. Check that Real-time protection is turned on

Real-time protection should always be on. It makes sure files are checked the moment you open or download them.

Turning on cloud-delivered protection

On the same settings page you'll find Cloud-delivered protection. Make sure it is turned on. Cloud-delivered protection sends information about suspicious files to Microsoft for analysis. This helps detect new threats faster.

Automatic sample submission

Below that you'll find Automatic sample submission. When Windows Defender encounters a suspicious file that is not in its database, it can automatically send a copy to Microsoft for analysis. You can choose from:

  • Always prompt (manual check)
  • Send safe samples automatically
  • Send all samples automatically

For the best protection, choose automatic submission, but if privacy matters to you, choose always prompt.

Tamper Protection

This important feature prevents malware from changing your security settings. Make sure Tamper Protection is turned on. This prevents viruses from turning off Windows Defender.

Running and scheduling scans

Windows Defender offers several types of scans.

Types of scans

  • Quick scan: Checks the most common locations where malware hides. Takes a few minutes.
  • Full scan: Checks your entire system. Can take hours, depending on the size of your drive.
  • Custom scan: Lets you select specific folders or drives.
  • Microsoft Defender Offline scan: Restarts your computer and scans for malware that hides while Windows is running.

Running a scan

  1. Open Virus & threat protection
  2. Click Scan options
  3. Select the type of scan
  4. Click Scan now

Scheduling automatic scans

Windows Defender runs scans automatically, but you can adjust this:

  1. Press Windows + R
  2. Type taskschd.msc and press Enter
  3. Navigate to Task Scheduler Library, Microsoft, Windows, Windows Defender
  4. Double-click Windows Defender Scheduled Scan
  5. Go to the Triggers tab
  6. Click New to add a schedule
  7. Set when the scan should run
  8. Click OK

Setting up Controlled folder access

This is a powerful feature that protects you against ransomware by preventing unknown programs from making changes to your important folders.

Turning on Controlled folder access

  1. Go to Virus & threat protection
  2. Scroll to Ransomware protection
  3. Click Manage ransomware protection
  4. Turn on Controlled folder access

Adding protected folders

By default your documents, pictures, videos and other personal folders are protected. You can add more folders:

  1. Click Protected folders
  2. Click Add a protected folder
  3. Select the folder you want to protect

Allowing apps

If a legitimate program is blocked:

  1. Click Allow an app through Controlled folder access
  2. Click Add an allowed app
  3. Select Recently blocked apps or Browse all apps
  4. Select the program you want to allow

Setting up the firewall

Windows Firewall protects you against network attacks.

Checking the firewall status

  1. Open Windows Security
  2. Click Firewall & network protection
  3. You'll see three network types: Domain network, Private network and Public network
  4. Make sure the firewall is active for all network types

Allowing a program through the firewall

If a program does not work properly because of the firewall:

  1. Click Allow an app through firewall
  2. Click Change settings (requires administrator rights)
  3. Click Allow another app
  4. Browse to the program and add it
  5. Check the network types it is allowed to communicate on

Managing firewall notifications

  1. Click Firewall notification settings
  2. Choose whether you want to receive notifications when the firewall blocks a new app

App & browser protection

These features protect you while browsing and downloading.

Turning on SmartScreen

  1. Go to App & browser control
  2. Under Reputation-based protection, click Reputation-based protection settings
  3. Make sure the following options are turned on:
    • Check apps and files
    • SmartScreen for Microsoft Edge
    • SmartScreen for Microsoft Store apps

SmartScreen warns you about dangerous downloads and websites.

Blocking potentially unwanted apps

On the same page you'll find Potentially unwanted app blocking. Turn it on to block programs that may not be malware but do show unwanted behavior, such as adware.

Adding exclusions

Sometimes Windows Defender blocks legitimate files or programs. You can add exclusions.

Creating an exclusion

  1. Go to Virus & threat protection
  2. Scroll to Exclusions
  3. Click Add or remove exclusions
  4. Click Add an exclusion
  5. Choose what you want to exclude: File, Folder, File type or Process
  6. Select or type what you want to exclude

Be careful with exclusions. Only add items you are sure are safe.

Viewing protection history

Windows Defender keeps track of what it has detected and blocked.

Viewing the history

  1. Go to Virus & threat protection
  2. Click Protection history
  3. You'll see all recent detections and actions

You can filter by type: All, Quarantined items, Cleaned items, Blocked actions and Severe.

Updating Windows Defender

Windows Defender is updated automatically through Windows Update, but you can check manually:

Updating manually

  1. Go to Virus & threat protection
  2. Scroll to Virus & threat protection updates
  3. Click Check for updates

Making sure automatic updates are on

  1. Go to Windows Settings
  2. Click Windows Update
  3. Make sure automatic updates are turned on

Optimizing performance

Windows Defender can slow down your system during scans. Here are tips to minimize this.

Scheduling scans for quiet moments

Schedule full scans for times when you are not using the computer, such as at night or during your lunch break.

SSD users

If you have an SSD, scans are already quite fast. You don't need to worry as much about slowdowns.

Exclusions for developers

If you program or work with a lot of temporary files, consider excluding your development folders. This prevents Windows Defender from constantly scanning files that change quickly.

Frequently asked questions

Is Windows Defender good enough as your only antivirus?

Yes, for most users Windows Defender offers excellent protection. It consistently scores high in independent tests by organizations such as AV-Test and AV-Comparatives. Combined with common sense when opening attachments and visiting websites, Windows Defender is sufficient for the average home user.

Can I use Windows Defender alongside other antivirus software?

Windows Defender turns itself off automatically when you install another antivirus. However, you can turn on Periodic scanning, which lets Windows Defender run an extra scan now and then alongside your other antivirus. You'll find this under Microsoft Defender Antivirus options in the settings.

Why does Windows Defender block my program?

Windows Defender blocks programs it considers potentially dangerous. This may be a false positive. First check whether the program comes from a trusted source. If you are sure it is safe, you can add an exclusion or allow the program through the protection history.

How do I temporarily turn off Windows Defender?

Go to Virus & threat protection, click Manage settings and turn off Real-time protection. Windows Defender automatically turns itself back on after a while to keep you protected. This is useful when installing software that is wrongly blocked.

Conclusion

Windows Defender is a powerful, free security solution that offers more than enough protection for most users. By taking the time to set it up properly, you get the most out of this built-in security. Make sure real-time protection and cloud-delivered protection are on, turn on Controlled folder access for ransomware protection, and keep your system up to date. With these settings you are very well protected against most online threats.

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