When installing WMP 9 it leaves a watersign on your desktop. You can easily remove this with:
regedit:
HKey_Local_Machine\SOFTWARE\microsoft\system certificates\CA\certificates\FEE449EE0E3965A5246F00E87FDE2A065FD89D4
HKey_Local_Machine\software\microsoft\system certificates\ROOT\certificates\2BD63D28D7BCD0E251195AEB519243C13142EBC3
That's all