Screens · guide

Monitor flickering, and which of the two machines is doing it

By Alberto Gulotta · Updated 11 September 2026 · 16 min read

Monitor flickering comes from one of two places — the monitor itself, or the computer feeding it a picture — and each one has a test of its own. Microsoft’s takes ten seconds inside Windows. The monitor’s runs from its own buttons, with the computer out of the picture entirely.

Almost everything written about this fault answers only the first half. Microsoft’s page is a good page and it is about Windows: it opens by saying that “Screen flickering in Windows 11 is usually caused by a display driver issue or incompatible app”, and both of the answers its test can give are software. That is not a flaw in the page — it is what the page is for. It becomes a problem when you have a monitor that is failing and you spend a week rolling drivers back and forth, because the test you were given cannot return the word “monitor”.

The order is worth respecting even though the second test is the more conclusive one. The Windows test costs ten seconds and needs nothing; the monitor test needs you to work the buttons on the case and, for the stand-alone version, to unplug the video cable. Do the free one first, and read its result for what it is: it is not the monitor being cleared, it is the software being split in two.

1. Open Task Manager and watch the window, not the screen. Ctrl + Alt + Delete, then Task Manager; if that screen does not come up, Ctrl + Shift + Esc opens it directly. Ten seconds of looking decides between a driver and an app, which are the two software answers.
2. Before changing anything, try the reset that costs nothing. Microsoft: “In some cases, pressing Windows logo Key + Ctrl + Shift + B to reset your graphics driver may fix your issue. If this does not work, see if restarting helps.” The screen goes black for a moment and comes back; nothing is uninstalled.
3. If the flicker was in Task Manager too, go to the driver — backwards first. Microsoft’s order is roll back, then update, then uninstall, and the reason is in the first one: “If Windows Update recently made updates to your device, roll back your display driver.” Device Manager, Display adapters, right-click the adapter, Properties, Driver, Roll Back Driver. If the button is greyed out, that is an answer too: “Windows doesn’t have a previous driver to roll back to and won’t be able to complete this process.”
4. If Task Manager stayed still, the flicker belongs to an app. Microsoft’s treatment is to update it or remove it, and the note that matters is where it came from: an app from the Store updates from the Store, and everything else updates from its own maker.
5. Now ask the monitor. Run its built-in diagnostics from its own buttons or joystick, the ones on the front or the side edge of the case. The pattern is generated inside the monitor, so if the flicker is there as well, nothing on the computer can be the cause. Dell is blunt about what follows: “If the screen abnormality is present in the integrated self-test mode, contact Dell Technical Support for repair options.”
6. If the monitor’s own test is clean, swap the parts around it. Dell’s troubleshooting page puts a second monitor first: “If you have another monitor available, disconnect the current monitor, and replace it with the other monitor. This helps eliminate several factors that might prevent a video signal from reaching the original monitor.” The same logic applies to the cable, which is the cheapest part of the chain.

Two notes on the driver part, because it is where the most damage gets done by people trying to help. The first is Microsoft’s own order — roll back before update — which reads oddly until you notice the sentence that precedes it: the fault often arrives with an update, and going forward again is the one direction that cannot undo it. If you do decide to go forward, take the driver from the machine maker or the graphics chip maker and nowhere else; which generic driver to look for covers that, and a driver updater found through a search is a bigger problem than a flickering screen. The second is that both roll back and uninstall want an administrator: Microsoft states that “You must have administrator privileges to roll back or uninstall a device or driver package using Device Manager.”

And if Task Manager stayed perfectly still while the rest of the screen shivered, resist the driver entirely. That result points at one app, and the way to find it is to notice when the flicker happens rather than to rebuild the system around it. A screen that only misbehaves inside one program, or only while something is playing, is describing the culprit.

There is a third possibility that neither test names, and it is the one to keep in mind when both come back clean: the things between the two machines. Dell’s troubleshooting page starts its list with a second monitor and then goes to the accessories, because “Accessories like external hard drives, USB devices, Wi-Fi antennas, printers, and VR headsets can sometimes interfere with the boot process”. A cable is the cheapest thing in the chain and the easiest to swap; a docking station sits in the middle of the picture and is the last thing anybody suspects. If the screen is not flickering but blank, that is a different fault with a different route, and it starts at a second monitor that is not detected.

One last one, for a monitor that has settings you did not choose. Dell documents a reset to factory defaults through the on-screen display: “Dell monitors can be reset to factory default settings using the on-screen display (OSD) menu. This can be accessed using the buttons or joystick that is available on the Dell monitor.” It is the monitor equivalent of starting again, it takes a minute, and it is free. If the flicker survives it and survives the built-in test, you are no longer troubleshooting: you are deciding whether to repair.

Not covered here. It will not walk through refresh rates and resolution settings as a cure. Neither source it is built on treats them as the cause of a flicker, and a page that fills itself with settings to try is the thing this one was written against.

It will not tell you what a monitor repair costs. Neither of the two Dell articles read for this guide gives a figure, and the only thing either maker puts in writing about money is who pays when the damage was accidental.

And it will not become a Windows page. The test that names the monitor runs on the monitor, which is the half that the operating system cannot see. What holds instead is simple: the statement that screen flickering in Windows 11 is usually caused by a display driver issue or incompatible app, the instruction to check whether Task Manager flickers in order to determine which of the two it is, the two readings of that check, the graphics driver reset with the Windows logo key plus Ctrl plus Shift plus B, the order of rolling back before updating a display driver when Windows Update has recently made updates, the note that a greyed-out Roll Back Driver button means Windows has no previous driver to roll back to, and the requirement to have administrator privileges to roll back or uninstall a driver package, are quoted from Microsoft’s page on troubleshooting screen flickering in Windows; the list of screen abnormalities that the integrated self-test is for, the description of the self-test feature check as a way of checking the monitor as a stand-alone device when the screen remains dark or blank, and the instruction to contact support when the abnormality is present in self-test mode, are quoted from Dell’s article 000124390; and the second-monitor swap, the note about accessories interfering, the questions about the monitor having been dropped or having had liquid spilled on it, the statement that without an active accidental damage policy the owner covers the cost of repair, and the factory reset through the on-screen display menu, are quoted from Dell’s article 000132354.