Squashing smaller companies, destroying market innovation, releasing sub-par OSes just cause they can, overcharging because of their monopoly, continually trying to extend their monopoly into other markets, constant attacks on PC gaming through horrible systems like Games for Windows Live, practices of selling private information and holes in their security on Internet Explorer to anyone willing to pay, blatant robbing of ideas of other companies (Internet Explorer from Firefox, Vista from OSX, Zune from iPod, and numerous things from Sony and Nintendo), practices of buying out patents then just letting them sit so no one can ever use them and advance past their own creations, and most recently the creation of the Xbox 360, one of the least reliable pieces of gaming hardware ever made (STILL has >16% failure rate).
Fortunately for perhaps the world in general Microsoft is nearing the end of their days. Their expansion markets have all been cut off. Despite bleeding money into the 360 it's moving quickly into 3rd place worldwide, Zune was slaughtered by Apple, PC gaming was taken over by Valve and digital distribution, Google kicked them out of the internet and Firefox takes more internet explorer users every year. Google is very quickly nearing a position where they can begin to destroy Microsoft, and in 10 years Microsoft will be a shadow of their current self.
For the record, Bill Gates is a great guy. I really like Bill Gates. He was smart, innovative, and giving, but the company he created has become monstrous and a plague on technology and innovation.