microsoft.public.windowsxp.security_admin

I bring my personal laptop in to work with me and I have noticed things are
changed. I always log off ( I am admin. passord protected) and put it away
dont shut down. Several times when I open it back up and log on I have
noticed that some how or someone has changed the font size and I see it right
away on my desktop, all icons are tiny. I know who is doing this but how can
I check and see when it was done. And I am assuming that one would have to
be logged in as admin. to change my infor. too even if they looged in as a
guest. Is that correct? Any help would be very much appreciated.