A tip for you.
If you remove disks from optical drives when you are not using them, you will get a longer useful life from the drives.
If an optical drive has a disk in it, the mboard bios spins disks in optical drives while booting if an optical drive is listed in the boot order in the bios Setup settings in the right place, and in Win 95 and up, the disks spin when Windows is first loaded, and it spins them up when you access My Computer or Windows Explorer, or when you click on the drive's drive letter - most people are aware of that - BUT Win 95 and up also spins the disk at other random times, and when it does, it does not always spin it at a higher speed so you may not be aware it's spinning, and the led on the drive does NOT always come on when it does that.
The most common reason an optical drive fails to work properly is the sleeve bearings in the drive's motor have worn and deteriorated to the point there is too much friction in them and the drive can no longer spin the disk at even 1X, the original audio CD speed, or the motor won't spin at all.
Therefore, if you want the bearings in the drive's motor to yield you the longest possible useful life from the optical drive, try to remember to always remove disks from the drives when you are not using them.