Open two instances of Notepad++

From the documentation:

You can launch Notepad++ with the -multiInst Command Line Switches. This will enable launching extra instances when opening files by double click or right click. Any command line will do, including the one that you can access from the Properties of the desktop shortcut.

You can always send a document being edited to another instance from the View menu or the tab right click menu, or call Run -> Open in another instance, regardless of this setting.

To force one file per instance Notepad-like behaviour, see Notepad-like Behaviour. This will hide the tab bar, but you can restore it from Settings -> Preferences -> Tab bar.

You can also access the properties of the Explorer Context Menu, and plug the -multiInst switch in the command line available there.

The Settings -> Preferences -> Multi-Instance preference widget allows choosing between the way Notepad++ handles multiple instances:

• by default, us single instance mode
• always use multiple instances
• open session in new instance

When you open the second file, whilst it opens as a second tab you can just grab the tab and drag it out of Notepad++ to open it in a second session. Sort of like how Firefox, Chrome and IE do it with tabs.

Finally found how to do it:

1. Settings > Preferences > Multi-Instance > Always in multi-instance mode
2. If new a file, multi-instance is not working. Need to save this file first and then move the tab out of window.

There is a shortcut to open in new instance Alt + F6. Also if you want to open always in new instance than go to settings->prefrences->Multi-instance , here you can select option to always in multi-instance mode.