Is this an original OS CD ??
Is this the CD you received from SAGER with the laptop (if you ordered with OS)
Try putting the CD in first when the system is off and then start the system. You will be prompted (during or just after POST) as follows :-
Press any key to Boot from CD...
and you have to hit any key

if that doesnt work check in the BIOS to see if the boot sequence is CD, A, HDD...or whatever...make sure the CD is on top of the list.