Example: http://users.hogent.be/subedi/htm/nl/bio.htm 1st paragraph, third line.
If I view this file before uploading I see correct characters. I get correct characters if I download and view this file with filezilla as well. Its uploaded to my schools's server.
How can I display those characters correctly?
The encoding is being guessed at incorrectly by the browser.
You can fix this on your browser by telling it to use unicode/utf-8.
But in order to fix this for every visitor you should put a meta tag into your html that will tell user-agents to use utf8.
<meta charset="utf-8"/>