Without NTFS, you are gonna be very limited in what you can do as far as security settings. It's a good thing that he is logging under as "Guest" where he won't be able to install or uninstall anything.
Best bet is move the sensitive data to a removable disk/storage or if they are MS Word documents, you can set a password on them.
There are ways to remove My Computer and My Documents from the desktop, but of course he/she can always access any directory through win explorer of course.
Best bet is move the sensitive data to a removable disk/storage or if they are MS Word documents, you can set a password on them.
There are ways to remove My Computer and My Documents from the desktop, but of course he/she can always access any directory through win explorer of course.