Gamma Guard

Monitor brightness keeps resetting on Windows

If brightness snaps back after sleep, wake, HDR changes, or opening Windows Settings, another display setting or system event may be taking over.

Gamma Guard Sleep and wake HDR and GPU resets

Find the trigger

Brightness resets often happen after sleep, wake, HDR changes, driver resets, or monitor mode changes.

Gamma Guard restores dimming

If Windows clears software dimming, Gamma Guard can help reapply Display Dimmer's gamma dimming automatically.

Restore after events

Startup reapply, schedules, app rules, and gamma fallback can help keep levels consistent after common display events.

Common triggers

  • Sleep, wake, hotplug, or changing display modes can reset monitor, GPU, or gamma state.
  • HDR mode changes can change how Windows and the graphics driver handle brightness.
  • Monitor eco modes, dynamic contrast, local dimming, or auto brightness can override manual settings.
  • Multiple brightness utilities can fight each other.
  • Some systems clear software dimming after wake, driver changes, or display changes.

Gamma Guard for software dimming

If Windows, HDR, sleep/wake, or a display reconnect clears software dimming, Gamma Guard can help reapply Display Dimmer's gamma dimming automatically.

Watches for outside changes

It looks for gamma resets that were not caused by Display Dimmer, so normal slider changes still feel immediate.

Reasserts the current level

If your display was dimmed with gamma fallback, Gamma Guard restores that level instead of leaving the screen bright.

What to try

  • Turn on Gamma Guard if brightness snaps back after sleep, wake, HDR changes, or display mode changes.
  • Disable monitor auto-brightness, eco, dynamic contrast, and similar picture features.
  • Test with only one brightness or monitor-control app running.
  • Try HDR off for the affected display if resets happen when HDR changes.
  • Turn the monitor off and back on after sleep/wake problems to reset its control channel.
  • Use gamma dimming fallback when hardware brightness is unreliable after wake.

Display Dimmer options that help

Display Dimmer gives you multiple ways to keep brightness stable: Gamma Guard for Windows or GPU gamma resets, startup reapply after launch, and schedules or app rules for intentional changes throughout the day.

Gamma Guard

Detects external gamma resets and restores the current Display Dimmer brightness level.

Schedules and app rules

Reapply brightness based on time of day or the active app when automation should control the level.

Startup reapply

Restore saved brightness when Display Dimmer launches after a reboot or sign-in.

Gamma fallback

Keep visual brightness control available when DDC/CI resets, fails, or becomes unreliable.

Frequently asked questions

Why does brightness change back after sleep, wake, or reboot?

Common causes include HDR changes, GPU driver resets, Windows display mode changes, sleep and wake events, monitor eco modes, and other software resetting the display gamma or monitor state.

What is Gamma Guard?

Gamma Guard is Display Dimmer's protection for software dimming. When Windows or a display change resets the gamma ramp, Gamma Guard helps reapply the selected brightness level.

Can Display Dimmer reapply brightness after sleep or wake?

Yes. Display Dimmer can reapply brightness after startup and display changes. If hardware brightness is unreliable after wake, gamma dimming fallback can help keep the display visually consistent.

Does Gamma Guard replace DDC/CI?

No. DDC/CI changes a monitor's hardware brightness when supported. Gamma Guard helps protect gamma dimming fallback when Windows, HDR, sleep, wake, or a graphics reset changes the software brightness state.

Keep brightness where you set it.

Use Gamma Guard, startup reapply, schedules, and app rules to help keep brightness where you expect it.

Get Display Dimmer on Microsoft Store