How to start SSMS as a different Windows login

Question: I  am logged onto my desktop with my primary Active Directory ID.  I need to log onto a SQL Server with SQL Server Management Studio (SSMS) with another Active Directory ID - the alternative ID has   valid  SQL Server security privileges on the target SQL Server. 

How can I log onto the target SQL Server with the alternative login  , remain on my desktop and use the alternative Active Directory ID ?

Answer:   In an earlier post - How to start SSMS as Administrator ,   there is reference to the RUNAS command. Combining the RUNAS  with the the SSMS command line execute will get the result you need. 

Open the Command Prompt window & use similar to the below examples 

--example 1 : the full path to SSMS
RUNAS /user:mydomain\myaltID "C:\Program Files (x86)\Microsoft SQL Server Management Studio 18\Common7\IDE\Ssms.exe"

--example 2 :  using ssms shortcut 
RUNAS /user:mydomain\myaltID ssms

Once the SSMS is open , you can use some commands to confirm the current login.Returns the name of the login that connected to the instance of SQL Server.

SELECT ORIGINAL_LOGIN();