How to run secondary Skype after recent Microsoft update?
After reading Ian's answer, I find it is a great solution to this my question. I am posting my own answer just to share my findings based on Ian's link as I faced difficulty on using above answer's path and settings.


Copy the skype shortcut paste thereon to create new skype shortcut.
Rename it as you want just to distinguish from the primary shortcut.
Now, go to its properties and append following string in Target
property
Skype --secondary --datapath="C:\Login_1"
Hence the new full string will be "C:\Program Files
(x86)\Microsoft\Skype for Desktop\Skype.exe" Skype --secondary
--datapath="C:\Login_1"
Click on this shortcut and you are done.