CD/DVD ROM will not install

Toshiba laptop internal cd/dvd rom will not install. OS=XP. It worked at one point with same system and then stopped. External CD drives will not install (usb or pcmcia)System restore will not go back to when it worked. I’ve uninstalled/reinstalled the driver several times but device manager still shows driver conflict. XP support says no additional drivers are necessary. Stumped.