= 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 [http://support.microsoft.com/kb/311272 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 and 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 [http://www.7-zip.org/ 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 [wiki:TapRenameScript 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''