Vista - Duplicate Desktop Icons??

Whenever I place an icon on the desktop the darn thing appears twice. I
can't seem to figure out which of the several 'Desktop' folders windows
looks at to display desktop icons. Some of these 'desktop' folders contain
files that do not show up on the desktop at all. I am very confused and
have spent hours wasted, trying to solve this inconsistency. If anyone can
help me in the right direction, please do. Thanks so much, I would love to
be able to put stuff on my desktop again.