Surface
Windows 8
RROD
Anything else is probably something small and petty some people come up with to make their list look longer.

It is pretty weak that they couldn't sell in japan. It is like saying "I know i missed those shots but look at the shots I actually did hit. Isn't that awesome?" Failures are still failures.

Fable The Journey and Gears Jugdment

The only mistake they made was with the RROD, but other than that the Xbox has been sufficiently successful this gen. The Xbox is actually the one product that Microsoft has gotten right, and they are raking in decent profits from it now. What they really need to do is capitalize on the Xbox's success. They should make an Xbox handheld or an Xbox phone, or Xphone, that could really help branch their business.

RROD

Buying Rare/mismanagement of Rare

Other buyouts that don't make much sense. I'm sure are plenty but I can't think of most off hand. I didn't agree with Skype but w/e.

BING but in the long run could be profitable but that remains to be seen.

Having their own cell phones then killing it shortly after. Lots of wasted money in R&D.

Killing off Ensemble Studios (Halo Wars, Age of Empires/Mythology...)

Lots of people forget about Ensemble Studios.

Windows 98 and Vista

Releasing Windows Vista and buying AQuantive.

- Rare
- Hardly any new IP's this gen
- Windows 8

Ohh ohh OHHH!! I got one!! Making Steve Ballmer their CEO.

As someone who just jumped ship from MS, these are the things that really bothered me:

Every major game is a multiplat shooter
The only realy MS exclusive they have is Halo
Ripping off the Mii
Kinnect
The seem to focus less on games these days and more on multimedia features