My computer had a reinstall of Windows 7 and from then on my Headphone jack isn't working on my PC. I try to connect it to my speakers which I know work because I connect them to other devices aswell. But for some reason my headphone jack doesn't give any output or response. Don't know whether I have to install a driver and which driver if so?. Also I have a sound card, does that have any connection to my headphone jack on the top panel of my computer or not?