While installing Visual Studio Code - Insiders if you have added the path in the environment variable, then you can fire it from the command line by typing code-insiders right away.The command is bit verbose/long and for which you may want to change it to code-i or codi for example. In order to rename the command, navigate to the path C:\Users\User\AppData\Local\Programs\Microsoft VS Code Insiders\bin and there you will find a file with .cmd extension. Change the file name and it should work expectedly.