[ygra]

Notepad also doesn't save as ASCII by default but »ANSI«, the default legacy codepage configured for your Windows installation.

[apaprocki]

Yes, the default Windows code page -- many pieces of software don't realize that registry keys, file paths, etc. are all encoded in a different code page if you are running, for example, Japanese Windows. (Also, it isn't exactly Shift-JIS...)