my operating system is windows xp. i connect my speakers, and i don't get a sound out of them. i checked the connection, and they are properly connected. i also tried my headphones, and they do not work. this problem started since i installed a new windows xp in my computer. i click on control panel. then i click on sounds, speech, and audio devices. then i click on sounds and audio devices properties. then i click on volume tab, and it says, "No Audio Devices". then i click on audio tab, and it says, "No Playback Devices". the computer does not recognize my speakers. why? i need help. thanks.