Computer wont accept cd drive

when i unhook the cd-drive, it works fine when its on and i hook the drive up, its fine but it doesn't recognize the cd-drive. the power is there the drive opens and shuts but it isn't recognized and when i try to restart the computer, it says no operating system . i unhook the drive and windows shows up perfect, Ive tried downloading LTR-48246S software, that's not even working for Me