I work at a dentist office and we have upgraded to Window XP professional and a new version of our dental software. When we installed the the new window xp professional the speakers were not plugged into the computer. Now I have no sound. I have plugged the speakers up and still no sound and no new hardware is found. In my control panel and (sound and audio device) (volume) there is no audio device. What do I need to do to get sound. Please help.