|We understand that your CD drive isn't reading disks. The advice given in response 1 was to help you work out whether the problem is hardware or software related.|
BIOS stands for Basic Input Output System.
That is the "dragon brain" of the system that tells it it is a computer and instructs it how to use it's components. One of those basic instructions determines which device to boot up into operation. Your laptop may be set to boot up the harddrive as the first choice. What you want to do is try to get it to boot up from a bootable CD as first choice. To access the BIOS settings there will be a key or a key sequence you need to press when your system is just starting up. It may be F1 or F11 or some other key but you need to find out which and press it to get into the settings area. This has to be done before the operating system boots up.
Change the boot order to CD first, save the changes and reboot with a CD in the drive. If the drive fails to read in BIOS then the problem is hardware. If the drive will read a CD and boot off it then you know your problem is in the operating system. How you go about repairing it is determined by the results of that test.
One simple thing you can try is a lenscleaning disk.
Since your machine is running XP it is obviously a few years old. The laser in the drive may be failing as they do wear out over time.
Goin' Fishin' (Some day)