Go into Bios (hit the Esc button several times as soon as it's powering up)
If Esc doesn't work, then hit the delete button.
http://www.laptopbits.co.uk/technical/support3.htm
"BOOT FROM CD
The only reason we've included any details of BIOS settings on this site is that many customers will need to access the BIOS to alter their boot order settings. Most recent machines will boot from CD, which saves having to manually install CD drivers. Often this feature is turned off.
If you need to boot from your CD access the BIOS as described above and look for Boot Priority or Startup options. Set the machine to boot from CD, then Hard Drive."