Search Button Query

I share my PC with my Son and Daughter.What do I have to do,to stop my children,from finding my pictures,videos,docs etc when they use their search facility on their desktop. For example,my daughter was searching for a video of hers that she had downloaded,but her search results showed videos of mine which included part of the search name she used.
I would be very grateful if anybody can help me with this problem.

Create separate user account(s) for your children, then set user permissions on YOUR folders so that only your user can access them.