Everyone has that one Microsoft product they can't stand. What's yours?

Speaking as a fan of Microsoft, I've noticed a very strong trend across the internet. They love and defend a wide variety of MS products, but they always (and I mean always) have one or two things they don't approve of that come from the corporate giant. Sometimes it's Bing, sometimes it's Windows RT, and I've even seen a couple of people throw Outlook.com under the bus. For me, it's the Xbox division. I didn't have any interest in the 360 and hoped that the next gen one would pique my interests, but the One just looks like a clusterfuck to me, so I'm getting a Wii U. What's yours? I'm interested in seeing which single properties you guys think Microsoft handled wrong and why.