Citadel / Controls / LockScreen

Screen Locking

What does this control check?

This control verifies that your computer automatically locks its screen after a period of inactivity, and that unlocking it requires your password or PIN.

The risk: If your screen does not lock automatically, anyone who walks up to your unattended computer can access everything: your files, your emails, your passwords, and any system you are currently logged into. From your email alone, they can reset passwords for virtually any account — banking, work systems, social media — using the "forgot password" feature.

Why is this important?

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Unauthorized Access

An unlocked computer allows anyone nearby to access your work, send messages as you, access confidential information, or install malicious software.

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Data Protection

Screen locking protects sensitive information displayed on your screen from being viewed or photographed when you step away from your desk.

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Compliance

Most security policies and regulatory requirements mandate automatic screen locking to prevent unauthorized access to company systems and data.

How to fix this

Fix instructions for Windows

Windows offers several ways to lock your screen automatically. Find your specific error message below and follow the corresponding instructions.

"No screen lock configured"

Your computer has no automatic lock mechanism configured at all. The simplest fix is to configure your power settings so the screen turns off after inactivity, and to require a password when it wakes up:

  1. Click Start → Settings → System → Power & sleep
  2. Under Screen, set both "On battery power, turn off after" and "When plugged in, turn off after" to 10 minutes or less
  3. Then go to Settings → Accounts → Sign-in options
  4. Under "Require sign-in", select "When PC wakes up from sleep"

"Sleep timeout too high on AC (Xs)"

When your computer is plugged in, the screen stays on for too long before locking — giving anyone who approaches your desk too large a window of opportunity. Fix it:

  1. Click Start → Settings → System → Power & sleep
  2. Under Screen, set "When plugged in, turn off after" to 10 minutes or less

"Sleep timeout too high on battery (Xs)"

When running on battery, the screen stays on for too long before locking — a particular risk for laptops used in public spaces or shared offices. Fix it:

  1. Click Start → Settings → System → Power & sleep
  2. Under Screen, set "On battery power, turn off after" to 10 minutes or less

"Sign-in not required on wake from sleep"

Your screen turns off after inactivity, but when it wakes up it does not ask for your password — meaning anyone can press a key and get straight in. Fix it:

  1. Click Start → Settings → Accounts → Sign-in options
  2. Under "Require sign-in", select "When PC wakes up from sleep"
If this setting is greyed out, it is managed by your organisation's IT department. Contact them to have it corrected.

"Screen saver active but sign-in not required on resume"

Your screen saver activates after inactivity, but it does not lock the computer — anyone can press a key and get straight in without entering a password. Fix it:

  1. Right-click the desktop and select Personalize
  2. Click Lock screen in the left sidebar
  3. Scroll down and click Screen saver settings
  4. Check the box "On resume, display logon screen"
  5. Click Apply then OK

"Screen saver timeout too high (Xs)"

Your screen saver is correctly configured to lock the screen, but it takes too long to activate — more than 10 minutes. This leaves your computer unlocked for too long when you step away. Fix it:

  1. Right-click the desktop and select Personalize
  2. Click Lock screen in the left sidebar
  3. Scroll down and click Screen saver settings
  4. Set Wait to 10 minutes or less
  5. Click Apply then OK

"Screen lock inactivity timeout too high (Xs)"

Automatic screen locking is configured on your machine, but the timeout is set to more than 10 minutes — leaving your computer unlocked for too long when you step away.

This setting requires administrator rights to change:

  • If you are the administrator of your own machine — open Settings → Accounts → Sign-in options and reduce the inactivity timeout to 10 minutes or less.
  • If your machine is managed by an IT department — you cannot change this yourself. Contact your IT department and ask them to reduce the screen lock timeout to 10 minutes or less.
💡 Good habit: Whatever method locks your screen automatically, you can always lock it immediately by pressing Windows + L. Do this every time you step away from your desk, even for a minute.

Enabling Screen Lock on macOS

  1. Click the Apple menu in the top-left corner
  2. Select System Settings (or System Preferences on older versions)
  3. Click Lock Screen
  4. Set "Require password after screen saver begins or display is off" to Immediately
  5. Set "Turn display off on battery when inactive" and "Turn display off on power adapter when inactive" to 10 minutes or less
Tip: You can set up Hot Corners to lock your screen instantly. Go to Desktop & Dock → Hot Corners and assign a corner to "Lock Screen".
💡 Good habit: You can lock your screen immediately at any time by pressing Control + Command + Q. Do this every time you step away from your desk, even for a minute.

Verifying the fix

After making changes, Citadel will verify this control automatically during its next check. You do not need to do anything else.

To test immediately: Lock your screen manually (Windows + L on Windows, Control + Command + Q on macOS) and confirm that you are prompted for your password or PIN to get back in.