What color are the 4 diagnostic LEDs are rear of the tower?

When was last time you changed the battery on the motheboard?

Power off and disconnect PC from the wall. Press/hold power button on the tower for ~15 sec. Open the case and remove the battery from the motherboard. Press/hold the power button again for ~30 sec. Replace the battery (right side up!), close the case and see if it boots. If it does, chances are you need a new motherboard battery.

Ron

All Green. Have tried the power disconnect and battery drain.

The system attempts to boot but gives the corrupt or missing config. It will attempt to boot from the Dell operating system (XP Pro) CD but hangs when it gets to the inspecting hardware configuration. I tried a brand new hard drive but got the same results.

I figure the mother board took a hit when the ups malfunctioned when I powered it on yesterday.

Can you test the XP CD on another system to see if it's the disk itself? If you have more than one optical drive, try the other one.

Since it's got 4 green LEDs, it might not be the motherboard. Strip the motherboard down to bare essentials. Disconnect all peripherals and network connections, remove all PCI cards except video. Reseat RAM modules in their slots. Pop the battery to clear NVRAM and then try to boot from CD with only mouse, monitor and keyboard connected.

But if it's saying missing config, you need to run a Repair/Reinstall of XP and that requires you boot off the CD.

Ron 

Been there done all that. I took the system to my local computer shop. My first instinct is something on the board is fried or I got a nasty boot virus, either way my patience has expired. If my local geek cant get it back, I will junk it and replace the entire system, and use the wiped and formatted drive in an external enclosure as an auxillary drive for my other system.

Thanks for all the suggestions, but sometimes you have to cut your losses, walk away and start fresh.