CD-Roms not recognized….HELP!

Two days ago, out of nowhere, my cd/dvd-roms stopped being recognized by my computer. They are listed in the device manager but have the yellow exclamation point beside them. When I attempt to pull them up it says “Windows cannot initialize the device driver” Code 37. I have uninstalled and reinstalled but no help. Also, the headphone outs on my soundcard have also stopped functioning. I am computer savvy and have tried everything I know. It seems to be a driver issue…Microsoft 5.1.2535.0, but I can’t find a replacement and do not have my OS CD. My business depends on my computers running smoothly. Please help.