Tonight, I was impatiently waiting at our local computer store to hear the fate of our machine. It's being diagnosed and it's down to: a bad nic card pci slot (the slot itself!), a bad hard drive or IDE controller. I suspect it's dribbling fallout from the lightning strike we had this past May. Who knows. We probably would've saved oodles throwing it out the window and replacing it with an inexpensive new Dell.
Wish the machine luck.