On my son's Windows XP user account he can't insert pictures in a word document, but if we use my account on the same PC (this one!) we can open the same document and insert the same picture files with no trouble. Any ideas why?

On his account it opens a box to select the file type, and even though it's set to JPEG, we get no preview and it says some nonsense about not recognising the file. It won't let us copy/paste them either.