Fix-Flickering-MPO

Stop screen flickering on Windows 10 and 11 by turning off Multiplane Overlay (MPO).

One registry value · One restart · Undo anytime

 

Quick start · How it works · Verify · Undo · Troubleshooting · FAQ

---

Overview

My screen kept flickering while AdGuard for Windows was running. Turning off a Windows display feature called Multiplane Overlay (MPO) fixed it, and AdGuard keeps running as normal.

This repo packages that fix, a one-click undo, and what you should know before you use it.

Note

This is the same registry value NVIDIA provides as its official workaround for MPO flicker (support article 5157).

Is this for you?

The fix is likely to help if you see any of these:

• The screen flickers while AdGuard for Windows is running
• Black flashes on the desktop or inside app windows
• Flicker or stutter while moving or resizing windows
• Flicker in videos, browsers, or streaming and remote desktop windows
• Problems that only appear with more than one monitor, especially at different refresh rates

Quick start

1. Download Fix-Flickering-MPO.reg.
2. Double-click it, then click Yes → Yes → OK.
3. Restart your PC.

Important

The fix takes effect only after a restart.

Tip

Your browser may warn that .reg files can harm your device. That's a generic warning for registry files. Open this one in Notepad and you'll see it's only four lines.

Prefer the command line?

From a terminal opened as administrator:

reg add "HKLM\SOFTWARE\Microsoft\Windows\Dwm" /v OverlayTestMode /t REG_DWORD /d 5 /f

Then restart your PC.

How it works

Windows has two ways to put together the picture you see. By default it uses MPO: the graphics card gets separate layers, such as a video and the rest of the desktop, and combines them as the image goes out to the monitor. That saves power and lowers latency. But some combinations of graphics card, driver, monitor and app don't handle it well, and the result is flicker.

This fix turns MPO off, so Windows combines everything into one image itself before sending it out.

flowchart LR
    A[Apps and video] --> B{Multiplane<br/>Overlay}
    B -->|On, Windows default| C["Graphics card combines<br/>separate layers on the way out<br/>(can flicker on some setups)"]
    B -->|Off, this fix| D["Windows combines everything<br/>into one image first"]
    C --> E[Monitor]
    D --> E

Loading

What the file changes

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Dwm]
"OverlayTestMode"=dword:00000005

Line	What it does
Windows Registry Editor Version 5.00	Tells Windows this is a registry file.
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Dwm]	Opens the settings key of the Desktop Window Manager, the part of Windows that draws the desktop. It's machine-wide, so it applies to every user and needs admin rights.
"OverlayTestMode"=dword:00000005	Creates a 32-bit value named OverlayTestMode, set to 5, which tells Windows not to use MPO.

That's the whole change. Nothing is deleted or installed, and nothing runs in the background.

Trade-offs

	MPO on (Windows default)	MPO off (this fix)
Who combines the layers	The graphics card	Windows
On affected setups	Flickers	No flicker
GPU work during video	Lowest	Slightly higher (a little less laptop battery life during video)
Borderless games with an overlay on top	Normal input lag	Input lag can be slightly higher
AdGuard and other apps	Work normally	Work normally

Verify

Run this in any terminal:

reg query "HKLM\SOFTWARE\Microsoft\Windows\Dwm" /v OverlayTestMode

Output	Meaning
OverlayTestMode REG_DWORD 0x5	The fix is on.
ERROR: The system was unable to find the specified registry key or value.	The fix is off (Windows default).

Note

Don't rely on dxdiag. Its MPO MaxPlanes line can still show a number above 1 with the fix on. On the test PC it shows 3, and the flicker is gone.

Undo

1. Download Undo-Fix-Flickering-MPO.reg.
2. Double-click it, then click Yes → Yes → OK.
3. Restart your PC.

It deletes OverlayTestMode, which puts Windows back to its default with MPO on.

Prefer the command line?

From a terminal opened as administrator:

reg delete "HKLM\SOFTWARE\Microsoft\Windows\Dwm" /v OverlayTestMode /f

Then restart your PC.

Troubleshooting

What you see	What to do
Nothing changed after applying the fix	Make sure you restarted, then run the check in Verify.
The check doesn't show 0x5	Apply the fix again and click Yes on the administrator prompt.
The check shows 0x5, but the screen still flickers	Your flicker may have a different cause. Some people also report that certain Windows 11 24H2 and 25H2 builds ignore this value. Undo the fix and update your graphics driver.
The flicker came back after a Windows update	Run the check and apply the fix again if needed.

Still stuck? Open an issue with your Windows build, graphics card and driver version.

FAQ

Is it safe?

It changes one registry value, it's the same workaround NVIDIA provides, and the undo file removes it completely.

Do I need an NVIDIA graphics card?

No. MPO is a Windows feature and Windows itself reads this value, so it applies to NVIDIA, AMD and Intel graphics alike.

Do I have to uninstall AdGuard?

No. AdGuard keeps running. Only MPO is turned off.

Why is it called "OverlayTestMode"?

That's the name Windows uses internally. Microsoft doesn't document the value, but it's the one NVIDIA tells its users to set for this problem.

Will it survive updates?

It's a normal registry value, so it should. If the flicker comes back, for example after a major Windows update, run the check in Verify and apply the fix again if needed.

Compatibility

It should work on Windows 10 and 11 with any graphics card, because MPO is part of Windows. Tested on:

Windows	Windows 11 Pro 26H2, build 26300.9818
Graphics card	NVIDIA GeForce RTX 5090, driver 621.14
Monitors	2 (main monitor at about 280 Hz)
App that caused the flicker	AdGuard for Windows 8.0.5595

Credits

• LeerBox found that this fixes the AdGuard flicker, tested it, and made this repo.
• NVIDIA published the OverlayTestMode value as an official workaround in support article 5157.

License

Released under the MIT License.

---

If this fixed your flicker, a ⭐ helps other people find it.