Latin characters

[tognaco]

I've just installed XAMPP and everything seems to work properly, excepto for the Spanish and portuguese characters. Wherever those characters should appear, a question mark appears instead. I am speaking about characters such as ñ, ã , ç, á, Ó and so on. Of course, before writing here, I have double checked that the same website with exactly the same files is correctly shown in a production server. Any idea how to fix this problem?
Thanks in advance.