1.You maybe have a virus that corrupted some files. 2.Maybe it needs cleaning. 3.Try to re-install the drivers. 4.The CD-ROM drive could be bad. 5.Try an external CD-ROM drive and see if it works.
does it show up in the bios & device manager? is there an yellow exclamation mark or unknown device in device manager? what error does it give you when trying to read a disk?