Using multiple skype accounts at a time in single system

It's official trick provided by Skype team to run multiple Skype accounts at a time.

Open Run Window by press Windows key + R,

copy paste following line based on your your OS arch

For 32bit OS
"C:\Program Files\Skype\Phone\Skype.exe" /secondary

For 64bit OS
"C:\Program Files (x86)\Skype\Phone\Skype.exe" /secondary

hit enter, Skype application will open

If you’ve changed the installation path for Skype, you need to enter full path for the Skype.exe file.

This will work only on Windows Operating System with desktop installation of Skype.