I installed Mach3 on my laptop with parallel adapter. It did the parallel port check O.K. When I load the program, the reset flashes and it will not stop when clicked on. It has a message saying External EStop Required. What do I need to do to reset the program?

Changing the Active state of the Estop in Ports & Pins / Input Signals should do it.

It should be pointed out that because of the various and many problems associated with laptops using a parallel port this method of operation is not supported by Artsoft. You should be using an external motion controller (such as the ESS, etc.) with your laptop.

Tweakie.

Thank you. That did it.