When your Compaq Evo D510 starts up, it looks to each of the on-board devices, including the floppy drive, CD-ROM or DVD drive, and the hard drive, for the system files it needs to successfully boot up. While the standard boot order works well most of the time, sometimes a computer user needs to change the order in which the D510 reads the media. For instance, if you need to boot from a CD or USB device, you need to first go into the computer set-up and change the boot order so that the computer looks to those devices before checking the hard drive.
Log on to your computer and click on the "Start" button. Choose "Shut down" from the menu and confirm that you wish to shut down the computer. Wait for the D510 to shut down completely.
Press the power button on the D510 and watch for the Compaq logo to appear. Tap the "F10" button repeatedly until the "Entering Setup" message appears.
Use the right arrow key to highlight the "Advanced" menu and choose "Boot order." Highlight each device listed and use the up and down arrow keys to move it up or down in the boot order.
Press "F10" to exit set-up. Choose the "Save changes and exit" option to save the changes you made to the D510 boot order.