http://ftp.dell.com/Manuals/all-products/esuprt_desktop/esuprt_dimension_desktops/
dimension-4700c_Owner's Manual_en-us.pdf
Disconnect the hard drive data cable and turn off and back on. There should be an error.
Another failure has occurred.
• Ensure that the cables are properly connected to the system board from the hard
drive, CD drive, and DVD drive.
• If there is an error message on your screen identifying a problem with a device
(such as the floppy drive or hard drive), check the device to make sure it is functioning properly.
• The operating system is attempting to boot from a device (such as the floppy drive or hard drive and crashing);
check system setup to make sure the boot sequence is correct for the devices installed on your computer.