My Windows 7 installation had Russian localization.
When I encountered errors, I thought to translate the errors to Google into English. I decided to change the display language to English. In "Region and Languages" I chose a display language: English ("Keyboards and Languages" tab) and then restarted.
Some parts of error messages in the Log File Viewer of SQL Server Agent 2012 are still in Russian. I decided to change "Language for non-Unicode programs" (in "Region and Language" → "Administrative") to "English (United States)" as well, and then restarted.
Russian parts of new errors turn to ????????????????????
(seemingly encoding error).
What is going on?