Phantom program?

Hi, I had an older version of Mcaffee Uninstaller on my
computer a few years ago. Apparently I didn't know what I
was doing because I must have removed it the wrong way a
few years ago. I recently purchased and tried to install
a new version, but it stopped the install, telling me that
a previous version was still installed. It told me to
use "ass/remove programs." Well, that tells me a program
has to be installed to be uninstalled, even though it is
on the list. Huh? I've run the full gamut from
unchecking all the MCaffee items in startup tab on
MSCONFIG, Run the old Windows RegClean program, run
Registry First Aid (in which I personally went through a
thousand items, making sure every single on that was
MCaffee was deleted, run Spybot, and guess what? It's
still there supposedly. As a last ditch, I've searched
through every single Windows folder. How do I actually
get rifd of this thing once and for all, so that I can
install the new Uninstaller? Thanks In Advance. P.S. I
can not do the install again and then uninstall routine
because the first Uninstaller was a downloaded program.