Fix 0xC0262324: Duplicate Graphics Mode ID Error

Quick answer: Uninstall your GPU driver with DDU in Safe Mode, then reinstall the latest stable driver from the manufacturer. That clears the duplicate mode ID.

I saw this error first on a client's gaming rig last month. He had just installed a modded driver for his RTX 3080, and suddenly his second monitor wouldn't display. Event Viewer showed 0xC0262324 — the system was trying to register a display mode that already existed in the mode set. That's the core issue: either a driver messed up the mode list, or a corrupt config file has duplicate entries for the same resolution and refresh rate.

This error comes from the DirectX Graphics Kernel (dxgkrnl.sys). When Windows tries to build a mode set — a list of supported resolutions and refresh rates — for a display, it checks that each mode ID is unique. If two modes share the same ID (like 1920x1080 @ 60Hz appearing twice), it throws 0xC0262324. Common triggers:

Installing a beta or modded GPU driver
Using a custom resolution tool like CRU (Custom Resolution Utility) and not cleaning up old entries
Corrupt EDID data from a monitor
Messing with the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers

Step 1: Boot into Safe Mode and run DDU

Don't just uninstall the driver in normal mode. Windows keeps old driver files cached. Use Display Driver Uninstaller (DDU). Download it beforehand.

Boot into Safe Mode (hold Shift while clicking Restart, then Troubleshoot > Advanced Options > Startup Settings > Restart, then press 4).
Run DDU. Select your GPU vendor (NVIDIA, AMD, or Intel).
Click Clean and restart. This wipes the driver, the registry entries, and the mode set cache.

Step 2: Reinstall the stable driver

Download the latest Game Ready or PRO driver from the manufacturer's site — not a beta. If you were using a custom tool like CRU, skip that for now. Install the driver with a Clean Installation check box (NVIDIA has this under Custom). This tells the installer to remove old profiles and mode sets.

Step 3: Reboot and test

After the driver installs, restart normally. The error should be gone. If you still see it, check your monitor's EDID. A busted EDID can inject duplicate modes. Try a different cable or a different monitor to isolate it.

Alternative fixes if the above doesn't work

Use CRU to clean the mode list: If you know what you're doing, open CRU, delete all duplicate resolution entries, then restart. Only do this if you're experienced — one wrong delete and you lose a supported resolution.
Reset the registry manually: Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers. Delete the Configuration key (don't worry, Windows rebuilds it on reboot). Then restart.
Try a system restore point from before the error started. This can undo whatever config change caused the duplicate mode.

Prevention tip

Never install beta or modded GPU drivers on a machine you rely on for daily work. The driver model is complex, and one bad mode ID can cascade into blue screens or missing displays. Stick to the manufacturer's WHQL-signed drivers. If you use CRU, always export your current config before making changes so you can revert.

I've seen this error in the wild maybe a dozen times. Nine times out of ten, a clean DDU wipe and reinstall fixes it. The other times are hardware — a dying monitor or a bad cable that corrupts the EDID. If you're still stuck after these steps, drop a comment with your GPU model and Windows version.