See the Section at the end if you are using untangle.

Download openvpn gui at http://openvpn.net/index.php/open-source/downloads.html#latest-stable

Run installer

Leave the components section as default.

Accept the TAP driver install

Right click on OpenVPN GUI and select properties

Go to Compatibility tab and select “run this program as administrator”
(It requires admin priviledges because it needs to write routes for the new VPN tunnel. Without, it will connect but won’t know how to reach the other network.)

Get your OpenVPN configuration files from the system administrator. Copy and paste them into C:\Program Files\OpenVPN\config

ca.crt (certificate authority)
jason.crt (client certificate)
jason.key (client secret key)
jason.ovpn (client configuration). Here are the contents of jason.ovpn:

client
dev tun0
cert jason.crt
key jason.key
ca ca.crt
remote vpn.server 1194

Now you can launch OpenVPN GUI by double clicking the icon on the desktop (the one we just set to run as admin). This will launch the OpenVPN GUI into the system tray.

Click on system tray, right click on OpenVPN GUI, left click “Connect”.

If all goes well, you will successfully connect. The OpenVPN GUI systray icon turns green. Now you are on the Virtual Private Network!

Troubleshooting:

If you can’t connect, double check you have the correct config files in

Untangle: Download or Distribute OpenVPN clients

If you happen to be using untangle as the OpenVPN server you can download the untangle openvpn client and configs from the untangle administration web interface. This greatly simplifies your setup as everything is bundled inside the setup.exe. Just download and install and connect.  This requires untangle version 7.4.1 or higher to be compatible with Vista or Win 7. If you are using an older version, click “download a key for all other clients” (see screenshot below) and follow the instructions from the top of this page. If you want more control, you can use the above instructions for new versions of Untangle too.

From untangle web interface:

1. From main Untangle screen. OpenVPN rack, click on Settings
2. Clients Tab
3. Click “Distribute Clients”

4. Then click to download OR enter the email address to send it to.

5. Install on client computer and connect. Everything is done for you..

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002bE10318}

look through the list of subkeys (0000, 0001, etc)
DriverDesc keyword will tell you which network adapter. For example, “NVIDIA nForce Networking Controller”
when you find it, right click and add -> new -> string value

new keyword:

Value Name: = NetworkAddress
Value Data: = your new MAC, with no space or : For example, 0019DB71C830

then type:

ipconfig /release
ipconfig /renew
ipconfig /all   (to verify the new mac took)

Now your a l33t Winblows H4|<3r! If you want to go back to your hardware MAC, remove the NetworkAddress key and restart the interface.

FYI, in gnu/linux follow these simple steps to change your MAC address

ifconfig eth0 hw ether 00:19:DB:71:C8:30

if you get this error

SIOCSIFHWADDR: Device or resource busy - you may need to down the interface

do this

ifconfig eth0 down

and try to change the MAC again.