NVIDIA Windows VBIOS Vix Loader

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Loads a modified VBIOS for an NVIDIA GPU on Windows without flashing it. The image is stored in the GPU's driver registry key, where the NVIDIA driver looks for a VBIOS override when the device starts, and the device is restarted. unload removes it again. The card's flash chip is never written.

Thanks to @pantsoftime (overclock.net), whose original vbios_override work this project family is built on. Without it, none of this would have been possible.

To modify the VBIOS, use NVIDIA VBIOS Vix Editor. For Linux, see NVIDIA Linux VBIOS Vix Loader. This repository only loads the VBIOS on Windows.

This project is not affiliated with or endorsed by NVIDIA. NVIDIA and GeForce are trademarks of NVIDIA Corporation.

Warning. A modified VBIOS can raise power, clocks and voltages beyond the card's design limits. You can damage hardware. Keep a copy of your original ROM and use this at your own risk.

What it does

load writes these values in the GPU's driver key, HKLM\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\NNNN:

It also deletes romOverride00 to romOverrideFF if present, flushes the key, reads the values back and restarts the GPU with pnputil /restart-device. If the restart fails, restart Windows.

These are the same vbios and EnableGpuFirmware values that mVolt+ writes when it loads a BIOS file, so a BIOS loaded with mVolt+ on the same GPU is replaced. This project is not affiliated with mVolt+. Other values in the key are left alone.

unload deletes vbios and any romOverride records, restores EnableGpuFirmware (or deletes it if it was absent), deletes VixLoaderPreviousEnableGpuFirmware and restarts the GPU.

It does not flash the card, edit the VBIOS, or change clocks, fans or power limits by itself. unload returns the key to its state before the first load, except that an override written by another tool (mVolt+ vbios or romOverride records) is not restored; in that case load says so, and unload leaves EnableGpuFirmware as that tool set it.

Status

If you try it, please open an issue with the GPU, driver version and result.

Requirements

• Windows 10 or 11, 64-bit.
• An administrator account. The window program asks for administrator rights when it starts; run the command-line tool from an elevated PowerShell ("Run as administrator").
• NVIDIA driver 616.56 or newer (status shows the version).
• A payload file for that exact GPU model (same PCI device ID).

Which file to load

The file must contain exactly one VBIOS for this GPU's PCI ID with a valid checksum. Full flash dumps with two banks are refused: export a single-chain payload with Vix Editor's command-line tool (nvbios.exe).

With Vix Editor 0.1.11 or newer, saving an edited Ada or Ampere copy also saves <name>-loader.bin next to it: load that file. The commands below do the same from the command line.

• Blackwell: the ROM saved by Vix Editor after editing, or any edited single-bank dump (for example from GPU-Z). If it is refused because of two banks, run .\nvbios.exe normalize edited.rom payload.bin.
• Ada: the GSP firmware loads at most 512 KiB counted from the legacy image, so the payload must be relocated: .\nvbios.exe normalize edited.rom payload.bin --representation ada-relocated-v2. Larger payloads are refused.
• Ampere GA102–GA107: the same 512 KiB limit. Use .\nvbios.exe normalize edited.rom payload.bin --representation ampere-relocated-v1.

Usage

Window

1. Download vbios-loader-gui.exe from the releases and check it against SHA256SUMS.
2. Run it. Windows asks for administrator rights (it writes to the GPU's registry key).
3. Select the GPU in the list. The list shows each NVIDIA GPU with its PCI location, driver version and override state.
4. Click VBIOS file... and choose the file. The window checks it for the selected GPU right away and shows either OK (family, bytes to store, sha256) or why it is refused.
5. Click Load (the same as load), read the confirmation (GPU, file, registry changes) and accept. With Restart the GPU now on, the GPU is restarted (this can take up to 45 seconds); with it off, restart Windows afterwards.
6. To go back to the card's own VBIOS, select the GPU and click Remove override (the same as unload).

Every result and warning is also written in the Messages area. The window is in Spanish when Windows is; the Language menu, or vbios-loader-gui.exe --lang en / --lang es, changes it. It is dark when Windows uses the dark app mode; the Theme menu, or --theme light / --theme dark, changes it.

Command line

Download vbios-loader.exe from the releases, check it against SHA256SUMS, and open an elevated PowerShell in its folder.

# List NVIDIA GPUs: index, PCI location, driver version and override state.
.\vbios-loader.exe status

# Show what would be written, without writing anything.
.\vbios-loader.exe load .\payload.bin --gpu 0 --dry-run

# Store the override and restart the GPU.
.\vbios-loader.exe load .\payload.bin --gpu 0

# Remove it and restart the GPU.
.\vbios-loader.exe unload --gpu 0

• Select the GPU with --gpu INDEX (as shown by status) or --pci BUS:DEV.FN (for example --pci 01:00.0). With a single NVIDIA GPU the selection can be omitted.
• --no-restart writes the values without restarting the GPU; they apply at the next restart.
• --json prints machine-readable output.
• Exit codes: 0 done, 1 refused or failed (nothing written unless the message says so), 2 invalid command-line arguments (nothing written), 3 values written but the GPU restart failed (restart Windows), 70 unexpected internal error, 130 interrupted (Ctrl+C).

The override stays in the GPU's registry key until you remove it, so it applies again at every Windows start. A clean driver installation or a driver update can recreate the driver key and drop the override. Run status after updating and load again if needed.

From source, with Python 3.11 or newer: pip install . then vbios-loader status or vbios-loader-gui, or python -m nvidia_vbios.windows_loader status / python -m nvidia_vbios.windows_loader.gui with src on PYTHONPATH.

If the GPU does not start

Test first on a GPU that is not driving your display (use the integrated graphics or another card for the screen), so you can always run unload.

If Windows shows no image or the GPU fails in Device Manager:

1. Boot into Safe Mode: hold Shift while clicking Restart, then Troubleshoot → Advanced options → Startup Settings → Restart → 4 (Enable Safe Mode). Without a usable desktop, turn the PC off during boot two or three times (or boot Windows installation media → Repair your computer) to reach the same Troubleshoot menu. The NVIDIA driver does not load in Safe Mode, so the screen works there.
2. Open vbios-loader-gui.exe, select the GPU, turn off Restart the GPU now and click Remove override; or, in an elevated PowerShell, run .\vbios-loader.exe unload --gpu 0 --no-restart (use the GPU's index from status). Then restart Windows normally.
3. If that does not work, open regedit and go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}. Open the numbered subkey whose DriverDesc is your GPU (status shows it as driver_key). Delete vbios. Set EnableGpuFirmware back to the value saved in VixLoaderPreviousEnableGpuFirmware, or delete EnableGpuFirmware if it says absent. Then delete VixLoaderPreviousEnableGpuFirmware and restart.

Tests

PYTHONPATH=src python -m unittest discover -s tests

The tests use synthetic files and a fake registry; they run on Linux and Windows and never touch a GPU or the real registry. The workflow in .github/workflows/build.yml runs them on Windows, builds vbios-loader.exe and vbios-loader-gui.exe with Nuitka, checks that the window opens (with a screenshot), and publishes tagged versions as releases with SHA256SUMS and the third-party license texts.

License

Copyright (C) 2026 panchovix. GNU General Public License v3.0 or later (GPL-3.0-or-later), see LICENSE: you can use, study, change and share it, and changed versions you share must stay under the same license. See also THIRD_PARTY_NOTICES.md. Version 0.1.0 was released under the MIT license.