I can't find my disc drives any where.

Hello,
I've got a desk top mutt of a computer that I built in school. Everything was working fine until recently, but now my drives won't show up any where on my pc. I've tried locating them in my computer, deleting upper and lower class filters (there wasn't either of the two filters present), restoring my computer to a later date and no disc drive ever showed up... I'm so confused at this point as to what I can do. if you have any other advice please let me know I'm just so fed up at this point I am almost willing to buy new drives.