trashed public use computers

[PERLIB01]

We have five public use Internet stations not networked.  Each machine
has Menu builder and Winlock on it for security.  I find that if the
patrons 
want to  rearrange our computers, they will.  Therefore, can someone
tell me how I can reload each "messed with" computer quickly and easily?
Be gentle.  I'm a neophyte.  Thanks.  Carole Hayter, Midland Public
Library.