I  have struggled to get SS working on my laptop. At this point when I get into the program I get the message "ESTOP not assigned to Smooth Stepper input" I have a solid green light and a blinking red. Any clarification of what to do next would be appreciated
  Arnold

You need to have an E-Stop assigned to your setup. You can trick Mach/SS into thinking there is one there by setting the active state of the E-Stop to low and setting unused port and pins for it, really though you should have a real E-Stop fitted.

Hood

To add to the good advice Hood has offered: The EStop input is just there to the the SmoothStepper and Mach that A EStop has occurred and that they should stop sending out commands to the motors and such. This input by itself does not make an EStop system. I harped about proper EStops so much that a lot of folks are probably sick of hearing about it. No doubt you can find out more information about setting up a proper EStop on your machine with a quick search of this forum.

Thanks -hood and Jeff.  for the reply-How do I set the ESTOP to low?

Go into Settings->Ports&Pins->Inputs Tab scroll down to the Estop row, click on the active low column. If what I just said made no sense I would make the friendly suggestion to download the Mach manual from the documentation section of this website. It will be a big help in figuring out where certain settings are and what they do.