A file does not contain 'characters' (letters/symbols/glyphs/images that look like A or Z) but numbers. The (person configuring the) agent that displays those numbers decides the encoding (mapping of numbers to letters/symbols/glyphs/images).
See:
chcp
Active code page: 850
echo ÁÉÍÓÚ >0.txt
debug 0.txt
-d 100
0BFA:0100 B5 90 D6 E0 E9 20 0D 0A-E4 75 21 8A F0 2E A1 58 <-- these numbers never change
type 0.txt
ÁÉÍÓÚ <-- 850 glyphs for those numbers
chcp 1256
Active code page: 1256
type 0.txt
µگضàé <-- 1256 glyphs for those numbers
So decide which encoding scheme you want to/must use and then configure your display tools (console, editor, browser, ...) properly.