Hi ok it sounds to me like the computer isn't looking at the cd as the first bootable drvice. You need to access the bios and change boot options. To do this you have to tap...ummm usually del or F2 on early start up this will bring up the bios options. Look for boot options and move the cd / dvd to first bootable device and save and exit.
that should do it...good luck
Chris
May 2009