If you have a version of Windows that includes the Microsoft fax service (in Vista and Windows 7 known as "Windows Fax and Scan") then it must be disabled in order for snappy fax to gain access to the modem's com port.
Follow these steps: (Screenshots for Windows 7 are shown)
There is also a video tutorial showing how to do this on our tutorials page.
1. Go to Control Panel and click on Administrative Tools
2. Double click on 'Services'
3. Scroll down and find the 'Fax' service and double click on it
4. Click the 'Stop' button to stop the service and set the 'startup type' to 'manual'
