Your HP Compaq Presario computer uses a specific boot sequence to choose which drives to boot from when your computer starts up. This boot order allows your system disk to boot before other drives; however, you can adjust the sequence if you need to boot from another device. A common reason to change your Presario's boot order is for a reinstallation of Windows.
Restart your HP Compaq Presario computer.
Press the "F10" key as soon as the computer begins to boot. You will be taken to your computer's basic input output system, also known as BIOS.
Press the right arrow key three times to access the boot menu.
Scroll down and highlight "Boot Device Priority." Press "Enter."
Change the "1st Boot Device" setting to the drive you wish to boot from, such as your CD-ROM drive. Press "F10" to save and exit the BIOS settings page.