The "boot menu" allows you to temporarily boot from a different device, rather than your standard C drive. This is useful when you wish to boot from a CD, USB flash drive or separate hard drive but do not want to change your basic input-output system settings. This feature is rooted in the motherboard's BIOS, which means the key combinations, which are used to enter BIOS, may differ among models of Compaq Presario computers, now produced by HP. Some models may not offer this feature, which requires you to enter the BIOS for boot changes.
Restart or turn on your computer. You may see a screen that says, "Press XXX for Boot Menu" or "Press XXX for Setup." This indicates the key you need to push to enter the boot menu.
Press the key listed in the previous step continuously while the computer reboots. If you did not see a message on that screen, try continuously pressing the "Esc," "F12," "F11" or "F8" key.
Cycle through the list of boot devices using your arrow keys. Highlight the device from which you wish to boot, and press "Enter" to boot from it. If you were unable to enter the boot menu, you may not have that feature on your computer. In this case, go to the next step to enter the BIOS and change the settings there.
Press the key you noted in step 1 for entering the BIOS. This might be the "Delete," "F1," "F2," "F10" or "Esc" key.
Navigate using your arrow keys to the menu titled "Boot Sequence" or "Advanced Boot Options." Find the listing for "Boot Sequence" or "Boot Order." Highlight the device from which you wish to boot and press "+" to move it to the top position. On some BIOS screens, you may simply be able to highlight the first position and press "Enter." You can then select the device from the submenu. Instructions are typically listed at the bottom of the BIOS screen.
Press the "F10" key to save and exit. You will now be able to boot from the chosen device.