How to Set Up Viscosity for Windows for OpenVPN


I’ve really enjoyed Viscosity for Mac since last year. It’s an inexpensive, drop-dead simple VPN client that works with OpenVPN-enabled firewalls such as SmoothWall. However, Spark Labs didn’t have a Windows version. I spent quite a bit of time trying to find a simple OpenVPN client for non-techie users, but wasn’t satisfied with what I could find.

Spark Labs released their Windows version of Viscosity. I sat down to figure out how to install the OpenVPN certificates.(If you want to try Viscosity, they have a 30-day trial.)


I will only cover connecting to a OpenVPN client similar to SmoothWall (using PKCS 12 files).

Install Viscosity

Download the installer from the Viscosity download page. Accept all of the defaults. There is an option to create a desktop icon, if you want.

Depending on your OS, the installer may require a .NET piece to be downloaded from Microsoft. Click on Yes and the installer will take care of it for you.


You may see a warning that Viscosity doesn’t have an official happy face from Microsoft. Click on Continue Anyway.

When the install is complete, allow the installer to run Viscosity so we can proceed to setting it up for use.


Configure Viscosity

You’ll see a one-time Welcome to Viscosity screen. Close it to continue.

At this point, Viscosity will be running in your task bar (usually in the lower right-hand corner of your screen). The default icon is a lock in front of a circle:

Click on the icon and select Preferences….

There are couple of defaults in the Preferences window which I personally like to tweak. These are optional.

  1. Under the General tab, I select Start Viscosity at Login since I use it frequently.
  2. Under the Appearance tab, I choose the Leopard Colored menu icons because they boldly announce the connection status. Again, personal preference.


Install OpenVPN Certificates


There are two steps here. One is the creation of the VPN certificates, and the other is installing the certificates into Viscosity.

Create Certificates

I will use SmoothWall as an example simply because it’s a firewall I have ready access to. Refer to your documentation on how to do it on your firewall. SmoothWall has an option called Download Client Package (zip) which provides a single convenient .zip file that contains the two files we need.

Unpack Certificates

Copy the file to the machine you’re installing Viscosity on and extract them (assuming a zip file). Certificates are installed using the + button in the lower left corner of the Connections tab.

Navigate to where you put the files. You’ll choose the file that ends in .ovpn. It should import cleanly and show on the Connections tab. Now we need to click on the Edit button.

If you do not like the default name, feel free to change it on the General tab.


On the Authentication tab, change the authentication method to SSL/TLS Client (PKCS 12). Click on the upper Select button. (If it shows a file, click Clear.)

Choose the PKCS 12 file. SmoothWall uses the exention .p12. Finally, click Save.

The VPN connection should be ready at this point. Close the window.


Now that the connection is set up, you can click on the tool bar and choose the new connection. Ensure, of course, that you’re outside of the firewall first. 🙂

While Viscosity is connecting, you may see a message that A network cable is unplugged. This is normal and can be ignored.

Diagnosing Problems

If you’re having problems, click on the Details… menu item before connecting.

This window has three tabs which are a little hard to discern, in my opinion. The third one shows the progress of the connection, and may (or may not) provide useful information.


Further Help

I’m sorry I cannot help diagnose your particular system. For further assistance see the Spark Labs’ support page.


I don’t have any connection to the company. I’ve just been really happy with the product.


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