Benny,
Those problems usually happen when the text was typed using a non english keyboard.
The only way there is to correct this, and have it displayed correctly, is to replace, all the accents or tildes (àáâãåæçèéêëìíîïðñòóôõöùúûü), ñ´s and other non english characters using the windows characeter map that should have been installed on the accessories in the start menu.
Hope this can help