|Windows can't detect it if the bios doesn't detect it. |
It has to show up listed in the bios - in some bioses it doesn't - and/or it's model should show up on the screen while booting - although that may be obscured by a Gateway graphical screen, and you may have to disable displaying the logo in the bios to see that (and the hard drive model) .
Have you been fiddling with it's data cable connection or it's jumper settings or it's power connection since it last worked?
The following requires the computer is running, but it does not require the data cable be connected or that the optical drive is recognized in Windows.......
- the optical (CD or DVD) drive should eject, or retract, it's tray when you press the button on the front of it.
- when you insert a disk and retract the tray, the disk should spin briefly and the led on the front of it should come on briefly.
For a disk it's supposed to be able to read.....
- when a disk is inserted , if the led comes on for a lot longer than usual when a disk is inserted , or if it comes on then blinks on and off for a lot longer than usual, the drive is fried - it probably won't be recognizedby the bios or by windows when the data cable is connected to it.
- when a disk is inserted , if the led comes on but the disk does not spin, the bearings in the motor are seized - that's the most common cause of optical drives failing to have a disk in them recogized by the bios or in Windows, and the main reason they have no more than a one year warranty, but it doesn't prevent the drive from being recognized in the bios and in Device Manager and My Computer and Disk Management when the data cable is connected to it properly and it's jumpered properly if it's an IDE drive
- when a disk is inserted, if the led doesn't come on at all, either the power isn't connected to the drive, or the power supply is dying, or the drive is fried.
Failing power supplies are common and can cause your symptoms. They often still partially work before they die completely.
Optical drives require both +5v and +12v - if either is inadequate or missing it cannot work - if there is no +5v or not enough +5v, your USB ports won't work or won't work properly, as well.
Check your PS.
See response 4 in this: