I like some Microsoft products, but honestly, if they ditch Windows, and move their products to .NET... then ensure the .NET platform runs on Apple, Linux and a few other platforms (not terribly hard, since the tech is mostly there anyway), I think they might see some improvement.
TBH... I like what Windows was for a short time, in the 2000-XP era, when most of the security holes had been patched, and 7 is OK... but they are majorly ruining the UI. They are trying to be clever, edgy and push the envelope... but doing so in a manner that copies Apple, and tries to go one step further. So they not only lose the 'clever' appearance, for a copycat appearance, but they are copying some of the worst changes for the desktop environment, that Apple is making.
Then again... except for businesses, and a relatively small number of hobbyists, the desktop will be mostly eliminated in the next 5-10 years. So... Windows dieing on the desktop may not be such a big thing for MS. The people who will keep it, are probably the least likely to use Windows (except businesses). The desktop is for creating, most users are simply are fine with consuming, and they'll move to portable platforms which make that easier. Even the portable platforms are starting to be good with producing - particularly multimedia which doesn't require much typing. MS has the possibility to catch-up on the portable side, but it's isn't likely, even though they have a great mobile product, that market is fairly strongly set with other good/great products, and it will be a hard battle, one MS's prodigally inept PR department can only lose.