have an original error "error loading operating system", tried to reboot into safe mode, no joy...I had made a copy of my boot disk, won't recognize it--still shows "error loading operating system"

I think it might be a BIOS problem, or registry.

Have XP Pro (originally bundled with system), American Megatrends BIOS v. 1.54SIS, M848A 2003 release

Maxtor 80GB HDD, on AMD 2400 platform...