14gb missing from main partition

I had a virus. Rather than reformatting, I used XP pro's
feature to just rewrite the C:\windows directory and thus
fix the registry problems. This worked - I got my system
running again. However, when I selected all the contents of
C:\, it came up to around 26 gb of space taken. However,
when I right clicked on C:\ (the My Computer icon
properties), it said 40gb of C:\ had been used. WHERE is
this 14gb that I'm missing??? The only thing I can think of
is that when I reinstalled, something happened to my old
username that locked it up - it says 0kb for properties but
I can't open the folder nor delete it. This folder was my
old USERNAME. I didn't change it when I reinstalled (or
something) and my new one is USERNAME.FIRSTNAME.000

Please email me if you have a solution to this or
suggestions. I'm still have 38gb left total on my computer
so this is not urgent, but it would be convenient to know
what happened to 14gb of space!