I have installed Visual Studio 2017 RC, and by default it set language to my system language (Polish) so I was trying to change it to EN but in Options > Environment > Inter
You need reinstall VS.
Language Pack Support in Visual Studio 2017 RC
Issue:
This release of Visual Studio supports only a single language pack for the user interface. You cannot install two languages for the user interface in the same instance of Visual Studio. In addition, you must select the language of Visual Studio during the initial install, and cannot change it during Modify.
Workaround:
These are known issues that will be fixed in an upcoming release. To change the language in this release, you can uninstall and reinstall Visual Studio.
Reference: https://www.visualstudio.com/en-us/news/releasenotes/vs2017-relnotes#november-16-2016
Polish-> English (VS on MAC) answer: When I started a project and was forced to download Visual Studio, went to their page and saw that Microsoft logo I knew there would be problems... And here it is. It occurred difficult to change the language of VS on Mac. My OS is purely English and only because of the fact I downloaded it using a browser with Polish set as a default language I got the wrong version. I had to reinstall the version to the newest and then Visual Studio Community -> Preferences(in the environment section) -> Visual Style-> User Interface Language.
It translates to polish: Visual Studio Community -> Preferencje -> Styl Wizualny w sekcji Środowisko -> Język interfejsu użytkownika -> English.
If you don't see such an option then, as I was, you are forced to upgrade this crappy VS to the newest version.
You can CHANGE user interface LANGUAGE like this:
Open VS > VS Community > Preferences > Environment > Visual Style > User Interface language
Woala!!!
You can only install a language pack at install time in VS 2017 RC. To install RC with a different language:
You can have multiple instances of VS 2017 side by side so this shouldn't interfere with your other installation.
Disclosure: I work on Visual Studio at Microsoft.