[latebind (OP)]

Is it possible to increase the volume on the sound card by using software>? I have obviously set the volume to max inside the volume control on the task bar, but I want more more more!!

[glovesforfoxes]

If you want it for general media, VLC media player can turn volume up by 400% if you use the scroll on your mouse to turn it up.

http://www.videolan.org/vlc/

[LeeE]

Although some soundcards may have a headphone socket, they're really just pre-amplifiers and to drive loudspeakers you need a power-amplifier.

If you're referring to the sound level through headphones plugged straight into the soundcard then the answer is probably no because the amount of power that can be delivered to the headphones is going to be limited by the circuitry and traces on the motherboard and the soundcard.  If you're referring to loudspeakers then you need to turn up the volume on the power-amplifier, or get a more powerful one.