My IBM T20 Notebook is given me this message -PXE-E61: Media test failure, check cable- and then say -Operating System Not Found- ---- What do I do?

no solution, just more info, not all movie channels.

The error PXE-E61: Media test failure usually means the hard disk has failed or the hard disk needs re-seating or the disk controller is faulty. First - re-seat the hard disk and reboot the computer. If the computer does not boot up then reboot and go into the BIOS configuration to see if the BIOS detects the hard drive. If it doesn't detect the hard drive then it could be faulty.
Then the hard drive needs to be replaced in the computer/laptop, Windows installed and the computer or laptop's device drivers plus your programs etc. to get a functioning computer/laptop again.

Install os and Configure first boot device HDD

The issue might be with the laptop not being able to recognize the hard disk
Visit the below link for more information:
http://notebook-solutions.blogspot.com/2010/08/pxe-media-test-failure-error.html

See this on-line thread from other users. I'd be leary about the posts that advocated hitting the laptop...

http://www.nocrash.com/ncbbs/msgs/3247.shtml

Portable computers can suffer from bad connections easily, so the first thing you should check are that all cables and other connections are tight and seated firmly.

No; the message indicate absence of hard drive.
open the laptop and remove the hard drive and reinstall it.
if the message still appear then your hard drive is faulty.

Something went wrong with your last installation. try reinstalling windows. But, before that go to BIOS and check the BOOTING devices

It is trying to bbot up using network boot because it cannot find OS on the hard drive, you can turn off the network in the BIOS setup page, but more likely you have problem with the hard drive or the OS is corrupted.

Some BIOS allows for a hard drive diags. try it to test the hard drive, if ther is no such utility you need to test the hard drive anoter way.

Basically either the hard disk controller has failed or the hard drive is faulty. In most cases the hard drive is dead.
To check if the hard drive is OK, remove the hard drive and attach it to a USB hard drive adapter then plug it into a working computer's USB port. If the computer sees it as an external drive and you can view the contents of the external drive then the hard drive is OK.

check your harddrive, is it detected in bios ?
if no, it could be motherboard or hdd, but most of the time is hdd problem, so just replace it.
if yes, your operating system is corrupt, so you can reload your operating system.