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Fix a Second Monitor Staying Black After Sleep on Windows 11

A black second monitor after wake is usually caused by Fast Startup or a GPU driver timeout. Restore it in five steps.

by@guidox updated:10/26/26 time:10 min level:Intermediate works on:Windows 11 25H2, Windows 11 24H2
TL;DR

Windows fails to re-initialize the secondary display pipeline after sleep because **Fast Startup** caches a stale GPU state or the **TDR timeout** is too short. Disable Fast Startup and extend TDR to fix it.

Before you start

Requirements

  • Admin rights
  • Access to the primary display to navigate settings
Step by step

Instructions

01

Confirm the symptom

Put your PC to sleep via **Start > Power > Sleep**, wait 30 seconds, then wake it. If the second monitor stays black but the primary works, the issue is the display re-initialization path.

tipTry pressing Win+Ctrl+Shift+B to restart the graphics driver. If the monitor comes back, the GPU driver is the root cause.
02

Disable Fast Startup

Open **Control Panel > Power Options > Choose what the power buttons do**. Click **Change settings that are currently unavailable**, then uncheck **Turn on fast startup**. Save and restart.

control powercfg.cpl
03

Update or reinstall the GPU driver

Download the latest driver from **NVIDIA** (https://www.nvidia.com/drivers), **AMD** (https://www.amd.com/en/support), or **Intel** (https://www.intel.com/content/www/us/en/download-center/home.html). Choose a clean install if the option is available.

⚠ warningDo not use the driver Windows Update offers — it is often months behind the vendor release.
04

Extend the TDR delay in the registry

The GPU may need more time to re-initialize the second output after sleep. Add a **TdrDelay** value to give it 8 seconds instead of the default 2.

reg add "HKLM\SYSTEM\CurrentControlSet\Control\GraphicsDrivers" /v TdrDelay /t REG_DWORD /d 8 /f
tipRestart your PC after adding the registry value for it to take effect.
05

Verify after a sleep cycle

Put the PC to sleep again and wake it. Both monitors should light up within 5 seconds. Repeat the test three times to confirm consistency.

Troubleshooting

Common issues

Second monitor shows 'No Signal' instead of staying black

The monitor is losing the DisplayPort or HDMI handshake. Try a different cable or port on the GPU, and disable DisplayPort deep sleep in the monitor's OSD menu.

Win+Ctrl+Shift+B does not wake the monitor

The GPU driver is not responding to the reset command. Perform a clean driver install using DDU from https://www.guru3d.com/download/display-driver-uninstaller-download/ and reinstall the latest vendor driver.

FAQ

Frequently asked

Does the connection type matter?

Yes. DisplayPort is more prone to sleep-wake handshake failures than HDMI. If you can switch the second monitor to HDMI, test that first.

Will disabling Fast Startup slow down boot?

Slightly — expect 3-5 extra seconds on an NVMe SSD. The trade-off is worth it for reliable multi-monitor wake.

How to undo this

Delete the TDR registry value with `reg delete "HKLM\SYSTEM\CurrentControlSet\Control\GraphicsDrivers" /v TdrDelay /f` and re-enable **Fast Startup** in **Control Panel > Power Options**. Restart.

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