No you don't need a special video card. It should work on any computer that can run Windows 2000 or later, with all the Microsoft updates. You would need some sort of audio output to hear the music.
If you want to download some lessons, you can first test how well it works by downloading a free lesson from Lyle Ronglien titled "Rockit Jam". This lesson is available in the introduction page of the "Riff Workspace" application.
The free Riff Workspace application, which is required to view downloaded lessons is available here: