XP COMPUTER CD DRIVERS WON”T LOAD

I Built this computer for a customer who every month gets enough spyware and viruses. Now it won’t find his cd drives. I have tried uninstalling and reinstalling and system restore but it just appears back with an exclamation point saying the driver won’t load. One is a DVD Drive the other is a CDRW. I have scanned for viruses and removed a couple but the drives never came back. AMD 2000, 256K DDR, XP Home