
To add new switch into command line:
1. Create a shortcut that will start Iron (I use Iron Portable, but you may apply it for common version too)
2. Open Properties box for that shortcut
3. In "Target" field add new switch -single-process. For example, that command line could be:
D:\Sys\Iron\IronPortable\IronPortable.exe -single-process
4. Save shortcut
To run Iron in single process mode - launch it by running this shortcut.
As always when it starts you'll see warning on the top"
You are using an unsupported command-line flag: --single-process. Stability and security will suffer.
Just close the warning box. From my experience always running it in single process mode - its stability doesn't suffer at all. It will use less memory form your computer and run faster (switching between threads in one process is always faster than switching between different processes)...