Monitor goes black seconds after showing desktop

First, can you attach another monitor to the computer to check to see if it works?

If it does, then your monitor is going bad. Possibly the power supply.
If a second monitor acts the same way, then it's your video card.

Could be a power issue. If it doesn't show anything at all then that may be the case. It may also be the display itself. It would be a costly repair so you might be better off finding a new monitor.

Try shining a flashlight on the screen, or without the flashlight, try to see if you can distinguish anything on the screen at all, if you do, the backlight is dead, or the monitor has an internal most likely unfixable problem.

reinstall windows ur screen resolution is not accepted by monitor

oboy, One thing to try is the flashlight test. and get backto me with your findings. Tell me, does this lcd show a nice display only for 1-2 seconds and then a black screen when connected to a fully booted PC with Windows desktop displayed? Shine a bright flashlight 1-2 inches from panel and tell me if you see the WINDOWS START Button at lower left of screen even though screen is black! Get back to me if you can. I'm louie12fix on fixya or lmistyrel @ aol.com BYE for now.

If tried the monitor on two other computers with the same result -- definitly your monitor is faulty. Take it to the repair shop. To make double sure, run your computer with another monitor. If everything is fine now; you can blame the monitor.

I've had a very similar issue on many Dell Monitors. Mine have been under warranty and they usually send me a new monitor, but I believe the issue lies with the power supply within the monitor.

Monitor going black after a few seconds can be causd by a faulty power supply or inverter. Some monitors have both as one unit.
Sometimes it is basic failed capacitors, After that then I would look at transistors.
The average monitor from 17 to 20 and sometimes the 22s have usually 4 bulbs in them. One bad bulb will also cause the inverter to not fire up.
Bad bulbs usually show pinkish tint, or flickering or are dark at center top or bottom of the display.
ebays bammbammfran

Try connecting the wires properly. try changing the VGA cable. i had the same problem my screen goes black some times and pink i changed the VGA cable it was absolutely fine!!!
What is VGA cable
VGA Cables Adapters Converters and Devices C2G

visit a computer mechanic for further trobleshooting