What is the INF file format?
.inf is a configuration file that stores data in plain text using an INI-style structure. .inf files contain information about a given driver or application - such as manufacturer name, installation method (full installation or update), and destination paths. They can also include various default settings and a list of files the installer needs to copy.
.inf files are read by the Windows Setup engine and contain installer directives rather than content useful to end users directly. The presence of an .inf is not mandatory for all installers, but it is the standard format for device-driver packages: Windows matches hardware IDs listed in the file to detected hardware, then copies binaries, configures services, and writes registry values. Drivers can be installed manually via right-click → Install or the pnputil command-line tool.
The format also powers autorun.inf, which once allowed CD and USB media to launch programs automatically. Starting with Windows 7, AutoRun from removable drives was disabled by default because malware had targeted autorun.inf as an infection vector. Driver .inf files remain fully supported in Windows 10 and 11, where modern packages follow DCH-compliant "Universal INF" rules.
Security & safety
RISK: MEDIUMReading an .inf in a text editor is safe - it doesn't run by being opened. The risk is on INSTALL: an INF can copy files, add registry keys and install a kernel-mode driver (.sys), so a malicious driver INF can compromise the system. Only install INFs from trusted, signed driver packages (modern 64-bit Windows enforces driver signing), and be wary of unsigned 'drivers' from random sites. autorun.inf historically auto-ran malware from USB/CD (Conficker), which is why Windows now ignores autorun.inf on most media - treat an unexpected autorun.inf on a USB stick as suspicious. The companion signed .cat catalog is what establishes a driver INF's trust.
Format details
in a nutshell- Autorun.inf (CD/USB autostart) - A small INF on removable media telling older Windows what to run/icon to show on insertion; heavily restricted since the Conficker era for security.
- Generic application info / config file - Some programs reuse .inf for their own INI-style info or installation data, unrelated to Windows driver setup.
Programs that open INF files
Windows4 apps
Windows Notepad
Built-in Double-clicking an .inf may offer Install; to just read it, open Notepad first and choose the file. Built into Windows. 
Notepad
Open-source Open the .inf as text to read or edit sections (handles ANSI and UTF-16 INFs cleanly). 
Microsoft Windows (right-click > Install)
Built-in Right-click a driver .inf (one with a [DefaultInstall] section) and choose 'Install', or use Device Manager > Update driver > Browse and point it at the folder containing the .inf.
pnputil (built-in)
Built-in Add a driver package to the driver store from the command line: 'pnputil /add-driver path\driver.inf /install'. The supported way to stage driver INFs. 
macOS1 app
BBEdit / any text editor
Freemium Open the .inf to read it as text. (An INF only INSTALLS on Windows; on macOS you can only view/edit it.) 
Linux1 app
Any text editor (gedit, Vim)
Open-source Open the .inf to read its INI-style sections; it cannot install anything on Linux. Technical details
deep spec| File type | Plain-text INI-style installation and configuration script |
| MIME type | text/plain (also application/inf, application/x-setupscript) |
| Encoding | ANSI (legacy) or UTF-16 LE with BOM (modern driver INFs) |
| Structure | Bracketed [Section] blocks with key=value pairs; [Version] section is mandatory |
| Primary use | Windows Plug-and-Play (PnP) device-driver installation and component setup |
| Key directives | CopyFiles, AddReg, DelReg, SourceDisksFiles, DestinationDirs, Manufacturer |
| Integrity mechanism | Companion signed .cat catalog file; the .inf itself carries no internal checksum or signature |
| Installation methods | Windows Device Manager, PnP manager, right-click Install, or pnputil command-line tool |
| File identification | No magic bytes; identified by [Version] section with Signature="$Windows NT$" or "$CHICAGO$" |
| Typical file size | 1 KB - 200 KB |
| Modern compliance | Windows 10/11 requires DCH-compliant "Universal INF" rules - no OS-specific or co-installer sections |
| Hardware matching | [Manufacturer] and Models sections list hardware IDs (VID/PID) matched by the PnP manager |
| Related package files | Packaged with .sys (driver binary), .cat (signed catalog), and optionally .dll files |
| Notable variant | autorun.inf - same format used for CD/USB autostart; AutoRun from removable drives disabled since Windows 7 |
| Developer | Microsoft Corporation |
| Released | Windows 3.x / Windows 95 era (1990s); central to Plug-and-Play driver setup |
| Latest version | N/A (the INF format evolves with Windows; modern 'universal/DCH' INF rules on Windows 10/11) |
| Specification | learn.microsoft.com |
INF conversions
Community Q&A
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