<img src="assets/NSS-128x128.png" align="left" />nefcon

Windows device driver installation and management tool.

About

This little self-contained, no-dependency tool can be built either as a console application or a Windows application which has no visible window (ideal to use in combination with setup makers). It offers a command-line-based driver (un-)installer and allows for simple manipulation of class filter entries. Run nefconc.exe --help to see all the options offered.

Motivation

Windows Device Driver management is and always has been hard. The APIs involved are old, moody and come with pitfalls. Historically the devcon tool or nowadays pnputil have been used to offload these tedious tasks, but unintuitive and sparsely documented command line arguments and error propagation make them poor candidates for automation in e.g. setup engines. Having grown tired of these limitations I made this "devcon clone" available under a permissive license which offers the following highlighted features and more:

• Allows for true window-less execution
• Actively suppresses and works around user interaction inconsistencies ("reboot required" dialogs and OS-included bugs)
• Offers optional logging to stdout or file
• Sane command line arguments 😁
• Manipulation of class filter entries
• Supports installation of primitive drivers

How to build

Prerequisites

• Visual Studio 2022 (Community Edition is free)
• Windows SDK

Fresh clone / first build

Dependencies must be installed before the first build from Visual Studio:

1. Clone the repository and initialize submodules: git submodule update --init --recursive (ensures the vcpkg submodule is populated)
2. Open Developer Command Prompt for VS 2022 (or x64 Native Tools for x64/ARM64, x86 Native Tools for Win32)
3. Run prepare-deps.bat from the repo root (installs all platforms) or prepare-deps.bat x64 for x64 only
4. Build the solution in Visual Studio

Dependencies (argh, detours, easyloggingpp, neflib, etc.) are declared in vcpkg.json and installed via vcpkg (included as a submodule). The build will use existing vcpkg_installed if present.

Installation

Binaries are available to download in the releases page, just download and extract. However, if you are using a package manager, you can use one of the following options:

Scoop

This is a community-maintained source and might lag behind GitHub releases.

nefcon is available in the Extras bucket:

scoop bucket add extras
scoop install nefcon

Winget

This is a community-maintained source and might lag behind GitHub releases.

nefcon is available in the winget-pkgs repository:

winget install nefcon

Command Reference

All commands require Administrator privileges unless noted. Paths may be absolute or relative to the current working directory. GUID format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx (brackets optional). Check exit code ERROR_SUCCESS_REBOOT_REQUIRED (3010) when a reboot is needed.

| Command | Description | |---------|-------------| | --install-driver | Primitive driver install (Win10 1903+); uses DiInstallDriverW | | --uninstall-driver | Primitive driver uninstall | | --inf-default-install | Legacy INF with [DefaultInstall] (e.g. Btrfs, volume controllers) | | --inf-default-uninstall | Legacy INF with [DefaultUninstall] section | | --create-device-node | Create ROOT-enumerated virtual device | | --remove-device-node | Remove all matching devices and driver; cleans driver store when unused | | --add-class-filter | Add upper/lower filter to device class | | --remove-class-filter | Remove upper/lower filter | | --create-driver-service | Create kernel driver service | | --remove-driver-service | Delete kernel driver service | | --delete-file-on-reboot | Schedule file deletion on next reboot | | --find-hwid | Search devices by partial hardware ID (no admin) | | --enable-bluetooth-service | Enable local Bluetooth service | | --disable-bluetooth-service | Disable local Bluetooth service | | remove [HardwareID] | devcon-compatible device removal (device only, driver stays in store) | | -v, --version | Display version |

Driver installation

--install-driver — Installs a primitive driver via DiInstallDriverW. Use for INF-based software packages targeting Windows 10 1903+ that are not tied to hardware.

• Required: --inf-path (path to INF, absolute or relative to CWD)
• Pitfalls: INF must exist; reboot may be required (check exit code)
• When to use: Primitive drivers, DCH-compliant packages

--uninstall-driver — Uninstalls a primitive driver via DiUninstallDriverW.

• Required: --inf-path
• Pitfalls: Same as --install-driver

--inf-default-install — Installs an INF with [DefaultInstall] via InstallHInfSection. Use for legacy INFs (e.g. file system drivers like Btrfs).

• Required: --inf-path
• When to use: Legacy INFs with [DefaultInstall]; not for primitive drivers

--inf-default-uninstall — Uninstalls an INF with [DefaultUninstall] section.

• Required: --inf-path

Device node management

--create-device-node — Creates a ROOT-enumerated virtual device.

• Required: --hardware-id, --class-name, --class-guid
• Optional: --no-duplicates — skips creation if a device with the same hardware ID already exists (returns success). Recommended for upgrade paths to avoid duplicate device instances.
• When to use: Software-enumerated devices (e.g. HidHide, virtual HID)

--remove-device-node — Removes all devices matching hardware ID and class GUID, plus the driver from the driver store when no device uses it anymore. Also removes matching devices that currently have no driver loaded.

• Required: --hardware-id, --class-guid
• Behavior: One run removes all matching devices (not just a single occurrence); removes the driver copy from the driver store if no remaining device uses it
• Pitfalls: Reboot may be required

Class filter manipulation

--add-class-filter — Adds a service to a device class upper or lower filter list.

• Required: --position (upper or lower), --service-name, --class-guid
• Pitfalls: Reconnect affected devices or reboot to apply
• When to use: Filter drivers (e.g. HidHide on HIDClass)

--remove-class-filter — Removes a service from the filter list.

• Required: Same as --add-class-filter

Driver service management

--create-driver-service — Creates a kernel driver service.

• Required: --bin-path (path to .sys), --service-name, --display-name
• Pitfalls: Binary must exist; does not start the service

--remove-driver-service — Deletes a kernel driver service.

• Required: --service-name

Utilities

--delete-file-on-reboot — Marks a file for deletion on next reboot. May take ownership if access denied.

• Required: --file-path
• When to use: Cleaning up driver files, locked files

--find-hwid — Searches for devices by partial hardware ID. Does not require admin.

• Required: --hardware-id (partial match)
• Exit codes: ERROR_NOT_FOUND if no match
• When to use: Discovering device hardware IDs before install/remove

--enable-bluetooth-service / --disable-bluetooth-service — Toggle a local Bluetooth service.

• Required: --service-name, --service-guid

Logging

• --default-log-file=.\log.txt — Write execution details to file
• --verbose — Enable diagnostic logging

devcon compatibility

install [INFFile] [HardwareID] — Drop-in for devcon install. Creates ROOT-enumerated device and installs driver. The /r flag is not supported; check exit code for reboot requirement.

• Optional: --no-duplicates — skips device node creation if a device with the same hardware ID already exists; still updates the driver. Ideal for upgrade/reinstall scenarios.
• Optional: --remove-duplicates — when used together with --no-duplicates, removes all but one matching device node before the driver update. Solves the common problem of multiple device nodes with the same hardware ID accumulating due to past setup failures or script reruns. Has no effect without --no-duplicates (a warning is logged).

remove [HardwareID] — Drop-in for devcon remove.