BleepingComputer.com: Trouble booting up

My Emachines computer will not boot up. The advanced bios screen shows
>Removable Disk Priority Not Installed
>Hard Disk Boot Priority Not INstalled
>CD-Rom Boot Priority Lite-on dvdrw sohw
>Network Boot Priority Onboard Lan Device
>First Boot Device Hard Disk
>Second boot device CDROM
>Third boot device Removable
>Fourth Boot device Network

The computer boots up but stops on the following screen
Intel UNDI. PXE-2.0 (BUILD 082)
FOR REALTEK RTL8139(X)/8130/810x PCI FAST ETHERNET CONTROLLER v2.13

CLIENT MAC ADDR 00 13 D3 06 B5 B6 GUIDE FFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFFFFFF
PXE-E53: NO BOOT FILENAME RECEIVED

PXE-MOF: EXITING PXE ROM

You may want to change your CMOS battery...a dying battery makes the CMOS behave in strange ways sometimes.

CMOS Battery Replacement - http://www.liverepair.com/encyclopedia/art...cmosreplace.asp

The PXE reference indicates that the system is trying a network boot, using the NIC...rather than booting from the hard drive (as called for).

Louis