That message indicates that your system is trying to boot from the network, not the hard drive.
First thing...enter the BIOS/Setup...and verify that the hard drive is selected as the first boot device.
Also check the data and time indicated in the BIOS and see if it's accurate.
At times, when the CMOS battery weakens...it makes the BIOS settings and system function in an unexpected manner.
This may be corrected by replacing the CMOS battery.
CMOS Battery Replacement - http://www.liverepair.com/encyclopedia/art...cmosreplace.asp
. Ignore any instruction to write down CMOS settings, that instruction is dated and unnecessary today.