Aircastle & iv-cnc,
I believe that there may be a tad of confusion here as to what is being asked about.
My understanding is that AirCastle, wants to learn how to open a PDF using a button in mach.
I'm guessing that he wants to do that as part of something he is working on.
Along the way, he appears to have noticed that our MachStdMill (MSM) product has buttons which open pdf documents.
The MSM buttons work fine and I don't think that Aircastle is saying there is a problem with MSM.
If I'm mistaken about that, and Aircastle is an MSM customer, then the thing to do is to drop into the MSM support forums and get some help (www.Calypsoventures.proboards.com
I think the "quick blink" Aircastle describes is what he sees when using the batch file approach that iv-cnc suggested.
It's been some time since I ran a dos box batch file but that sounds like what I'd expect when shelling a batch file.
Shell opens the batch file, the batch file runs and then disappears. That happens quickly as batch files don't wait for any user input by default... so visually you see cmd DOS box flash open as a black window, the batch file executes (probably writing a few lines into the dos box that you don't get time to see) and then the cmd window closes - the visual result is quick black flash (as the cmd windows is a text window that is white text on black background).