What happens now when you power on? Nothing? Beeps?

You say you tried clearing the cmos? Changed the jumpers on board?

Try removing the video card to see if you get any beeps.

I removed the Nvidia card, started computer, it went into Self Test. I tried to get it out with no luck. Shut down. Started, got it to go into CMOS. Checked settings. The Power Management/APM was set to "Disabled", just as I thought. Exited and was prompted to start in safe mode. Ran scan disk. Restored to last week. It finished restoring and rebooted and immediately went into Self Test mode and then Standby.
( Stuck again.

Oh, forgot to add: 1 beep and yes changed jumpers on board to clear bios and still only 1 beep after removing video card.

Can you repeat the steps you took to get safe mode options & choose boot into vga mode?

It doesn't give me that option.

can you get back into safe mode?

or just for a shot in the dark try last good configuration first.

Yes, I got back into safe mode. By the way, when it's in CMOS, Safe Mode and on the Safe Mode menu screen it doesn't go into Self Test/Standby mode even if left idle for a long period of time. I tried Step-by-Step confirmation and made it all the way to the end before it went into Self Test. While in Safe Mode I tried to use the Power Management troubleshooter, but my mouse wouldn't work (cordless) and I couldn't get it to select the appropriate problem. So then I tried to go into Control Panel and it wouldn't go there either. I had it highlighted, and pressed enter repeatedly but it just sat there and control panel wouldn't open. Now I'm so frustrated I'm ready to enter a computer throwing contest. By the way, thanks for all your help and patience.

Format/Reinstall?

I think the goal at this point would be get back into the Device Manager & re-enable onboard graphics.

I am a little confused by your term Self Test/Standby? I think what I call BIOS POST must be what you call CMOS ... then your monitor itself has a Self Test?

Have you an old mouse you can try?

Perhaps you can enter Device Manager via start > run > devmgmt.msc

When my computer is turned off and the monitor is left on, it displays a floating box that says something like Monitor Self Test...Your Monitor is working correctly...Please check your connections to the power source...etc. But it has only done that when the computer is turned off until now. Now it just goes into that mode at will. Then after about 30 seconds it goes into Standby mode I guess. The screen goes blank and the green light turns to yellow. I can ctrl-alt-del and restart the computer and I can hear it working but the screen stays in Standby. CMOS is what my computer calls the area where you can change system settings for the BIOS. It stands for Complimentary Metal-Oxide Semiconductor. It contains the memory used to retain the date, time and system setup parameters.