I hate to throw away this LCD monitor before knowing absolutely that it's garbage.  I've gone through a troubleshooting PROCESS with it but want to give it one last check.

The monitor was working fine then one day I cold booted Windows, and when POST finished and when the Vista log-on screen appeared, the screen goes dark.  I can get the screen to come back if I shut down the monitor and turn it back on, but it only stays on for about 7 seconds. 

I tried plugging the monitor into another computer with XP and GOT the same problem.  I don't have another VGA cable to try so I used my multimeter to test the continuity of the 15 individual wires running through the cable  and they all checked out OK. 

I noticed a sticker on the monitor that says, "This monitor is PROTECTED my Gateway anti-theft software"  COULD this have anything to do with the problem?

If it has worked for years, then the software is not what the problem is, unless it has never worked on EITHER of these computers.
The only other thing it could be is that the line that checks for a video card is not properly sending, or receiving power.
That would cause it to go to sleep.

Do you know which pin controls the power?
no I don't know which pin controls the power, but I did test all of them and according the multimeter they're all working.  I used the continuity tester where you get a constant beep if all is working...   and each pin checked out OK


Edit: do you by any chance know what the OHM (resistance) value is suppose to be across each wire?   I'm getting continuity, but maybe not enough continuity.  Maybe there is a tiny brake in one of the wires that is allowing for continuity, but not enough of a connection exsists for proper amount of current to flow......if you catch my drift

If I can find out the proper OHM value, then I can check that against the actually Resistance reading on the wires    and if I'm getting something other than what the value is suppose to be, I'll try purchasing another VGA cable

Edit: uh, I think length of the VGA cable makes a difference in what the ohm value should be, I'll try to look around and just figure it outTry moving your cord while having the monitor connected, if the display comes online then its the cord.
I've already tried moving the chord around, while it is connected

...I do have an extra CRT monitor

To be sure the problem is not the cable, I could order a Female VGA Gender Changer, so I could plug the VGA cable into a computer lile normal, and then connect that to a CRT monitor.  If the monitor works then we can conclude that the VGA cable is good and the LCD monitor is bad.

If it doesn't work, then the VGA cable is bad and the LCD could still be good! I guess I could try the DVI interface on the LCD monitor as well, since there is one optional.  Maybe it's only the VGA interface that's bad.  ONe of my friends has a computer with a DVI video card, I try it in his computer and see what happends..