Why can the limited account see what I've been doing on Windows Vista?

Ok, I am the main administrator account on this computer. But today, my room mate was able to read my recent emails, and see what I recently changed... I'll show you a screenshot later. I downloaded windows live mail, because the windows mail that came with my computer is really confusing... And he was able to see a few emails that I had received while I was on my account... AND he was able to see what files I recently changed... But he was able to see them from HIS account... Here are a few screenshots...

http://i163.photobucket.com/albums/t316/...

http://i163.photobucket.com/albums/t316/...

How do I make that stuff private!?

Thanks.

Why can the limited account see what I've been doing on Windows Vista?windows media center

Im still using xp, but to make your docs etc privite on xp you can go to "my documents"%26gt; right click%26gt; Sharing tab, and tick "make this folder private".

maybe you can find something similar on vista

good luck =)