1 Ensure the laptop is powered from the mains.
2 Switch the laptop on and press the F12 repeatedly until you see the message – Preparing one time boot menu or Entering Bootmenu...
3 Place the recovery cd in the drive and close it.
4 Use down arrow key to select the CD/DVD option from the bootmenu. You will be asked to "press any key to boot from CD" – you only get 3 seconds to press a key! If you miss it repeat step 2
Or
Power the computer on at the initial bios screen press F2 to get into the bios. change the first boot device to the cd-rom then press F10 to save then exit. If you choose this option, once you have recovered the laptop you will have to repeat this process and change the boot devices to how they were before so make a note of them.
Hope this helps you.