You may have figured it out by now. Most PC's have a way of entering the BIOS setup during the initial power on self test ?POST?. Not knowing the model, but it looks like many DELL models use pushing F2 during the first couple of seconds or when the 'splash screen' is visible.
Other PC's use 'Enter' , 'ESC', 'Fn' + f1, etc....... during the POST. You may need to google your exact model for the right key or key combination.
In the setup menu, you should find an option to either permanently change the bootup sequence or temporarily. Insert the 'CD' , change the boot sequence and SAVE Changes + EXIT the BIOS setup. This should boot you to the restore CD. It has been a long time since I had to reload an OS, but the disk should walk you through a hard drive reformat and the OS reloading. You will spend a lot of time loading in service pack upgrades and your needed software.
