Apart from the anti-competitive practices mentioned by Tdol, I could cite many many cases of Microsoft's arrogance and cavalier attitude to international standards - but they'd make no sense except to an audience of software developers. There are also two instances in the histories of my various IT companies when Bill Gates deliberately misled the people he was negotiating with. I could say more, but it would expose this site to legal action. Besides, it's not what UsingEnglish is about.
Having left the IT world behind me 3 years ago, I thought my hatred had mellowed. But a few weeks ago it was aroused again when I e-mailed my sister with an attachment; it worked on my PC, and on those of everyone else I sent it to, but not on hers. It got as far as firing up Word, appropriately, but she had committed the heinous crime of not continuing to line the pockets of Mr Gates so it crashed unceremonoiously. I sent her instead a JPG attachment, which - because the Joint Photographic Engineering Group aren't a money-making body, but is made up of developers who are interested in products that work for everyone - worked beautifully.
This is a tiny and nearly insignificant instance. But it was enough to surprise me by reminding me of the strength of my feelings.
Generally, I'm not a fan.
And yet, Mr. Gates and his company have changed the world. My most recent computer (as powerful as the world's largest mainframe when I was in college) cost me less than my first a 286 with a 10 mb hard drive working at a blazing 8 megahertz. Not exactly a sign of an industry full of monopolists.
And, yes, I know that Gates doesn't make the computers, but they would all be ashtrays without an operating system.