@Jagganath69, here is a way to get exclusive session group of files :

• In a DOS console window, run the command notepad++.exe -nosession

• Note that I personnaly chose the ses extension as the session file extension ( Settings > Preferences > MISC. )

• Open, let’s say, three files, named A, B and C

• Use the File > Save session... option

• Save the current session, for instance, as First.ses

• Close Notepad++.exe

• Restart the same command notepad++.exe -nosession

• Open, this time, three other files, named D, E and F

• Use the File > Save session... option

• Save the current session, for instance, as Second.ses

• Close Notepad++.exe

• From now on :

  • If you run the command notepad++.exe -nosession -openSession First.ses, the three files A, B and C will ONLY be opened

  • If you run the command notepad++.exe -nosession -openSession Second.ses, the three files D, F and F will ONLY be opened

  • If you run the command Notepad++.exe, you should see all the files which were present in the current session, when you last closed notepad++

Of course, when you simply start notepad++.exe, the current session may contain :

• Files which are absent of all the particular sessions First.ses, Second.ses, …

• Files which are present in particular sessions ONLY

• Files which are present in all the particular sessions First.ses, Second.ses, …

Best Regards,

guy038

TBH, the behavior you’re describing sounds desirable in most cases, because I wouldn’t want all of my files that were open in a secondary instance to be closed if I closed and reopened NPP.