the post above is the best choice
if you'd like to do it with one keystrok;
cut and paste the following including quotes;
"C:\Documents and Settings\Administrator\Application Data\Microsoft\Internet Explorer\Quick Launch\Show Desktop.scf"
make a desktop shortcut
hit properties on the shortcut
then go to the box that says shortcut
then just hit any f key you don't use.
that'll do it, but for this to work, you need to keep the shortcut on the desktop, so jsut make it transparent, and you're done