The file most likely contains non-standard characters and your computer does not have the required Language Packs.

Language packs are used by your operating system to display characters in different languages. For instance, to view Japanese characters on an English copy of Windows you would need the Japanese Language Pack. Unfortunately, Windows XP does not have the same multi-lingual support of more recent versions of Windows, and it may be impossible to open files with these characters on your Windows XP computer.