My folder is gone !!!

Hello,

I share the computer with other people, so I have a folder with my name on it.
But one day a guy deleted things and stuff in my folder, so I got pissed off .... So I clicked on properties ... after that you could click on that you wanted to hide the folder ... after that I can not find it again :(

And a question .... Is there possible to make a password on a folder?

I'm sorry for my bad english, I come from Norway