I just bough new headphones and when I plug them into my laptop Windows 7 doesn't seem to recognize them at all. When I right click on the sound icon in the lower right and go to playback devices it doesn't show any headphones it just shows speakers. I also right clicked on speakers and checked "Show Disabled Devices". Also when I double click on speakers to show the speakers properties window under Jack Information it says "ATAPI Internal ATAPI Jack" and I can't click on it to enable or disable it. Also Controller Information (in speakers properties window) says Realtek High Definition Audio.
I would try to update/install new sound drivers but I have no clue what driver to install or how to find out what soundcard I am using, I think my soundcard is integrated into my motherboard but I'm not sure.
Also, my laptop is dual booted with Ubuntu and when I plug my speakers in Ubuntu sound comes out of the right ear only and sound also comes out of the speakers at the same time. So I know the jack and the headphones work (at least the right ear does).