Anytime a piece of hardware does not work your best bet is to seek the driver for your computer from the computer manufacturer's website or the motherboard manufacturer's website if your machine is a custom build.
You can use the Device Manager to confirm that the computer still sees the sound card you describe and you can only hope this is a driver problem only. If the driver does not fix it then you might be stuck using a digital pair of headphones as your soundcard or installing an external sound card in a spare slot inside your machine. It depends on how old your computer is but it more than likely uses PCIe slots and sound cards usually are sold in the PCIe x1 variety ...some low cost version just use a USB slot.
Kshipper