Introduction

The OpenVPN's Windows TAP-drivers consists of four files for each platform (32/64-bit):

• <something>.cat: contains cryptographic signature for the actual drivers
• <something>.sys: contains the actual driver
• <something>.inf: contains driver metadata

In addition, a tool called <openvpn-install-dir>\bin\tapinstall.exe is provided. It can be used (among other things) to install and unistall TAP-drivers manually. This tool is actually a simply a renamed ​Devcon.exe.

If you need to run OpenVPN on Windows Vista/7 64-bit you have to use signed TAP drivers. Unless you sign them yourself, you need to extract drivers from an existing OpenVPN installer. See below for instructions.

Installing an uninstalling TAP-drivers

Occasionally you may need play with different TAP-driver versions. In this case you can use tapinstall.exe from the Windows command-prompt. Below are some common commands; <id> refers to the driver identifier which is tap0901 for OpenVPN 2.2*. This identified may be different in older/newer versions. To view information about an installed driver use

$ tapinstall.exe hwids <id>

To uninstall the TAP-driver use:

$ tapinstall.exe remove <id>

To install a new TAP-driver use

$ tapinstall.exe install <something.inf> <id>

Extracting TAP-drivers from OpenVPN installers

Extracting TAP-drivers from an OpenVPN installer is relatively easy: you can use ​7-zip to open the installer executable. There are both 32-bit and 64-bit versions, but the latter are larger in size.

Renaming the TAP-driver

Look at this page for a script that can be used to rename TAP-drivers.

Some specifics in Win-7 x64

(added 2013-01-08) maybe - will be fixed / changed in further releases, but - for now:

Recently tried "openvpn-install-2.3_rc2-I001-x86_64" ("release candidate" for x64 platforms); OpenVPN installer do NOT created <openvpn-install-dir>\bin\tapinstall.exe; but it created additional folder in "Program Files" - Program Files\TAP-Windows; if NOT - unpack the installer package with {7-zip}, go to unpacked "$temp" folder and run tap-windows.exe (unfortunately, no any shortcuts are created in your system to any of the tools/files in this folder). To add another virtual TAP-adapter - go to "\Program Files\TAP-Windows\bin" and run ("as administrator" !!!) the file named addtap.bat