How to start different profiles with Google Chrome when startup?

You have to create a new profile folder and use a different Chrome shortcut with --profile-directory command-line argument to specify the profile's location

Here's how you can go about doing it;

1. Create another user from Chrome → Settings as described in this answer.

2. There will be a "default" profile directory & a "profile 1" directory in %localappdata%\Google\Chrome\User Data directory.

3. Create a new shortcut to Chrome: Name the new shortcut as you see fit (for example, "Chrome 2nd profile")

   Right-click the new shortcut, choose Properties, paste --profile-directory="profile 1" at the end of the Target field. The result on Windows 7 should be:

    C:\Users\YOUR-USER-NAME-HERE\AppData\Local\Google\Chrome\Application\chrome.exe --profile-directory="profile 1"
   

4. That's it - you can now use the regular Chrome or "Chrome 2nd profile" and any changes made in one won't correspond in the other.