Assalam alikum to everyone

Friends , Yesterday i bought a tv tuner card of MSI.Card is working well but i can nought hear any sound.I think problem is that card is support only mono type voice or speaker but i have only stereo type headphone .i have installed XP windows.Any body can help me how can i convert mono into stereo or how i can hear voice through this headpghone.NOte that headphone is working well in windows.Only give problems in MSI tv tuner(plus) card.
Thanks friends
i hope u will answer me very soon.