I admit it, I am a sucker for Top 10 lists. They are such great argument starters.
PCWorld.com has an interesting slideshow of the 20 worst Windows features of all time. I won't play the spoiler and spell out the whole list (which is by and large on the money). But here are a few items that jumped out at me.
The damnable mascot in XP search makes the list in a broad dig at XP's generally poor search abilities. To me, the devil dog merits its own category of shame -- it's not just bad, it's insulting, and it crept out into Office and other MS applications. And it kept alive the dark spirit of Bob, which I imagine is not on the PCWorld.com list only because Microsoft actually thought people would pay $100 for it.
My only addition to the list would be Windows Media Player. It works, but I can honestly say I have never seen a version of Media Player that compared favorably to iTunes or any other of about a million free media applications. And Microsoft has never been able to resist the temptation of using Media Player to perpetuate its own file types. Who on earth wants to rip music as WMA files?
At any rate, the PCWorld.com list should make for an interesting chat with your help desk staff. Passions run deep when it comes to Windows irritations.