On Windows, CANtact requires a driver. It's easy to install:
Download the driver INF file using this link.
Open Device Manager (Start -> Right Click on Computer -> Click "Device Manager" on the left pane)
Find the unidentified CANtact device in the list
Right click the device, choose "Update Driver Software...:
Choose "Browse my computer for driver software" then select the folder that contains the downloaded INF file.
Choose "Install this driver software anyway."
Note: This can be dangerous! The CANtact driver contains no code, only an INF file which is easily readable. However, we're looking into driver signing to keep everyone safe.
After the driver is installed, you're ready to use CANtact! You can find the device's port number in the device manager. In this example, it's COM14.
Using the CANard library, initializing the CANtact you need to then specify that COM port. For example here, using COM14 you would use the following line:
dev = cantact.CantactDev('COM14')