Computer seems to be creating mega duplicate files?

Hello all, my newest problem I can't seem to get a handle on is my computer is creating dup. files using up much space. I have been using the trial version of system mech. 6 & did a dup. file search. It came up with an astonishing 2.2g's of duplicate files. Ihave know idea why a computer would hic-up like that or how to resolve this problem. With system mechanic 6 it looks as if i would have to look at these files individuly & delete them 1 by 1, which would take a week? Anyone know what is going on with my computer. Its a hp 772n pentium 4 2.26ghz 512mb 80gb thanks in advance