Russification (or, for that matter, arabification)
If you have to run an old (pre-Unicode era) program, which relies on a restricted encoding set (such as a ‘95 Russian installer), the characters will be, unfortunately, chosen from the System font. This is usually MS Sans Serif and it is not prepared to show anything Cyrillic. All the messages would be strings of question marks.
You could buy a new Windows, a Russian edition. You could set the global character set for non-Unicode application to be an old cyrillic font - in Windows XP, select “Control Panel”, classical view, “Language and Regional settings” and go to the “Advanced” tab. Unfortunately, it requires a reboot and then it will mess all the English (or other language you use) pre-Unicode software.
Microsoft provided a tool for this job, available only for Windows XP and 2003, AppLocale. It allows you to start a legacy app, fooling it about the system-wide encoding, in the way Application Compatibility Toolkit fools it about the operating system you’re running, emulating windows 95 or NT.
The brightest idea (now, when we have hooks to build a home-made clone for AppLocale) is the fact that you can build a shortcut for such a fooled application, say “Russian Encoded Tetris”.