take a look at the cd you have. there a few cd with the restore set from dell/hp. make sure you dont have the driver or program disk..those are not bootable..there one that should say os restore unless the vendor put a restore partion on your pc laptop.
if there is one then hitting a f key at power up will lanch it. if the cd-rom having an issue with the disk..if it an iso image you can try and burn a usb stick from the iso. microsoft and other make isp to usb programs.