It is possible to connect to multiple networks using OpenVPN for Windows. Here are the steps, that enabled me to connect to 3 VPNs at once on my Windows 7 machine.
This guide was compiled from two StackOverflow answers:
There are limitations to this. Quoting answer by zoredache from the first link:
Obviously you will also need to make sure that nothing about your various VPNs conflict with each other. For example if one is modifying the default gateway you are probably going to have problems. If nothing is changing the default gateway and there are no overlapping IP addresses then you may be ok.
The key is to create multiple TAP adapters, one per every VPN connection.
After you install OpenVPN, you will have one TAP adapter automatically created (I already renamed it, but it was named “Local Area Connection 2” before):
Later, I created two more TAP adapters. After you install OpenVPN, you will also have utilities installed under Start/All Programs/TAP-Windows. Or you can search for it directly using “Add a new TAP”. The script needs to be executed with administrator privileges. Right click on the shortcut (try shift+right click, if it does not work) and “Run as administrator”:
Search for “View network connections”. You will see that a new adapter has been created. You should rename it and give it a simple descriptive name.
I created two additional TAP adapters and named all of them TAPVPN1, TAPVPN2 and TAPVPN3:
The last step is to update your *.ovpn configuration files. For every VPN, add a new setting “dev-node %ADAPTER_NAME%”, e.g.: