To get sound you must also connect the male-male stereo plug from the blue plug on the TV card, to the blue plug on your computer's soundcard, and also ensure that your sound settings are appropriately set.
To do this please go to Start > Control Panel > Sounds and Audio Devices (if you can't see that option, click on "Sounds, Speech, and Audio devices > Sounds and Audio devices).
Once you are in Sounds and Audio devices properties, please ensure that the "mute" box is not ticked, and that the device volume slider is set to "high".
Then click on the "advanced" button, and then go to the "options" menu, select properties and ensure that "Line In" is ticked, then click on the 'recording' option and make sure that "Line in" is selected.
Once done click ok and you should now see a "Line In" volume slider if there wasn't one previously.
Please ensure that both Line in, and Volume control DO NOT have a tick in "mute" and that their volume slider is set to maximum.