Actually, the windows doesn't remember kvga as separate device.
I tried to use the both kvga and vga in the same time, how I can see does kvga exists in device manager, but without success. The screen is black in any combination when kvga is plugged.
- kvga is unplugged and vga is plugged in kvga slot or
- kvga is unplugged and suitable vga is plugged in agp pro slot,
than the external monitor screen is displayed back again and kvga doesn't exists in the device manager.
I'll check tomorrow does somebody have changed the well known password (I doubt that three groups of administrators have the same well known password).