Hum, could work indeed, that iMacros for IE will catch the Name of the '.iim' Macro, will start IE if it was not already running, and will run the Macro in IE. If you've associated the '.iim' Extension with '', then hum., I'm not sure what will happen. I'm not completely sure what you mean with 'from windows explorer', if you mean in Windows Explorer, double-clicking on an '.iim' File, then yep, if you've associated the '.iim' File Extension with IE at the OS/Shell Level (=> with 'iexplore.exe'), the Browser (=IE) will be able to 'open' the File and display it as a '.TXT' File in a Tab.
OK, everything is 圆4 for you, for both your Environments. Hum, you are all a bit 'funny', posted their '.BAT' File(s) and what they tried but didn't mention their FCI (hum, and never bothered to check their Thread again after it got approved, so I guess they got it to work in the meantime but didn't bother to share the Solution, grrr.!), and you mention your FCI(s) (perfect.!) but don't mention what you really tried for Syntax. Macro must be started manually from within the interface. Starting any macros, demo macros included from windows explorer or command line results in iMacros for IE opening a blank tab, then sitting there, not actually running the macro. OPERATING SYSTEM=Windows 7 Enterprise English / Windows 10 Home English