i don't know excatly where to post this doubt, i feel by name it is a right place

i have installed MySQL on my windows XP os so as the data files resides in
c:\program files\Mysql\data\.....
and the back up files (.sql) are also available on the same system

and these files are so vulnarable any other user even though he is not an administrator of my system can easily delete these files
& couse serious worries

basically kindly advise please , how to safe guard my MySQL installation please