If not, just go back to the restore point prior to installing your new drivers. When i installed new drivers on my graphics card everything went haywire, sometimes you have totally uninstall the card then reinstall from fresh with earlier drivers. It's not the end of the world so don't worry! :)
try moving the sound card to a different pci slot and rebooting. The OS should recognise it as new hardware and install necessary drivers. Check in bios that it is set to plug and play operating system and you don't need to worry about IRQ's. Check in control panel sounds,advanced, are your devices muted? Hope this helps, could also be a faulty sound card.