Why this and not that ?

[bobheart]

This runs ?

@ECHO OFF
:START
START Firefox.exe

And this won't ?

Run("Firefox.exe", "", @SW_MAXIMIZE)

[CyberSlug]

What is the current directory?

Either try

Run("C:\Program Files\FireFoxFolder\Firefox.exe", "", @SW_MAXIMIZE)

or try

FileChangeDir("C:\Program Files\FireFoxFolder")

Run("Firefox.exe", "", @SW_MAXIMIZE)

Adjust path as needed; use @ProgramFilesDir if you want...

[bobheart]

Yes but why can a dos bat file run it with just the name and autoit needs the full path ?

[pekster]

Yes but why can a dos bat file run it with just the name and autoit needs the full path ?

My guess is that the working directory from your script is the directory that the script was run from. I'd further guess that a Run(@Comspec & " /c Firefox.exe") would work, since it did from your command prompt before.

[bobheart]

Bat file is running from my documents folder and the Run(@Comspec & " /c Firefox.exe") does not work .

[pekster]

Bat  file is running from my documents folder and the Run(@Comspec & " /c Firefox.exe") does not work .

Then if you run your call from the directory of the my documents folder, you should have no problems.

[sugi]

I guess there's a different reason for it. Windows saves the paths for some applications like iexplore.exe in the registry (HKLM\SOftware\Microsoft\Windows\Current Version\App Paths). If the program can be found there, it can simply be run using cmd /c start iexplore.exe. However if you're trying to run the program without using start (e.g. cmd /c iexplore.exe) it cannot find it because it's not within its path.