This question is (almost) exactly the same as this one : How to write directly French characters in Emacs and print them in LaTeX? You may read his question instead of mine, the only difference (I spotted) is that the OP uses Emacs and I use Windows Vista and Miktex. I have tried the proposed solution, but it doesn't work on my computer. Unfortunately, I can't post comments below the answer.
I am using Miktex (on Windows Vista) which I only recently downloaded ("complete" version). I have encountered problems with special characters. I can't write é,è,à... directly on my keyboard, instead I have to write \'e, \`e, \`a etc which is very cumbersome.
I am really ignorant when it comes to computers and software, I hope somebody can help me resolve this issue!
EDIT : I am using Texmaker. Also, I downloaded the complete Miktex from a french university but didn't get any further packages. Is the package babel included in the "complete Miktex" download?
Finally, when I say the proposed solution doesn't work