Gorilla CNC User,
Adding an additional PCI parallel port wont stop the problem you are having.
What is causing the issue is intentionally built in to the BIOS and operating system.
It is not a matter of a defective P.C. or parallel port
First the BIOS on the motherboard polls the port or interrupts
Secondly Windows also polls the ports and interrupts during startup.
The only solution is to add a charge pump and wire it so the motor drivers are disabled when Mach3 is not running.
Jeff...