hi,
When start computer up, it comes up with screen which SAYS:

Intel UNDI, PXE-2.0 (build 082)
Copyright (C) 1997-2000 Intel Corporation

For Realtek RTL8139(x)/8130/810x PCI Fast Ethernet Controller v2.13 (020326)
PXE-E61 : Media test failure, check cable
PXE-M0F : Exiting PXE ROM.

Reboot and Select proper Boot device
or Insert Boot Media in selected Boot device and press a keyHas this machine been moved recently ? ?
If so remove a SIDE PANEL and double check all connections especially the cables going to the hard drive.

Make sure to remove all power first.No computer hasn't been moved recently. I was using it in evenings and shut it down. next day evening turn it on and it came up with that message, as above. computer was fine before and GAVE no problems etc. Check the connections anyways...it sounds as if the hard drive is no longer being recognised and may have failed...was it making any noises ? ?listening to hard drive, it seems to have a buzzing sort of noise from it Go to BIOS. Make sure, that the boot order reads: floppy, CD, HD
Disable Boot from Network (wording is different on every machine, may say Integrated NIC, Network, PXE-xxxxxxx)