I think it just boils down to the fact that Windows is overpriced and people know it. As I think someone said up thread, if the full complete versions were like $30, $50, and $75 then I am sure the average person would buy them no questions asked. It would also help if they kept the versions simple. Should only come in 2 flavors not 10 or however many versions they have. Also most people think of Microsoft as crooks and they have their position in the world by breaking the law and illegal means and have never been fully punished for their actions. The fact that there is not another effective alternative to Windows after all of these years is not a coincidence and it is not due to people reluctence to learn another OS.
There's also the fact that Microsoft doesn't allow the more advanced user to pick-and-choose what to install. The fact that if you use nLite or some such program to strip everything you don't need out of it, you're essentially paying 90% of the price for stuff you don't have is quite a hard pill to swallow.
I have no idea why other people don't use it -- but I don't use it because I associate with people who use Microsoft Office and every time I open one of their documents in OpenOffice, the tables are all messed up. It's easier to just use what everyone else is using .. don't really feel like fixing documents people send me because the word processor I used to open it messed it up. Not counting niche Linux distributions and only taking into account Linux distributions targeted at general purpose workstation use, there are at least twenty different 'Linuxes' with varying levels of compatibility between each of them, and different methods of installing software. Among the distributions, there so many different APIs and implementations for presentation, sound, and video that commercial application developers don't know what to target when developing -- especially since some of those APIs may be abandoned by the developers because someone got into a fight with someone else. As far as Windows workstation users go, general purpose home/home office computing, there are exactly two options that they have to choose from with Windows 7 (Home Premium, Professional), and for an advanced user, Ultimate, making a grand total of three. Home Basic isn't even an option in the developed world and Starter is for a specific OEM niche. Out of those two or three options, the user can be reasonably sure the applications they've had since Windows 2000 will still run and developers need to write their software exactly once. They don't need to figure out whether they want to target Ultimate, Professional, Home Premium, XP, or 2000. Their application will work* in all of them. I disagree that there is not another effective alternative to Windows. OSX is an effective alternative and it's effective for the exact same reasons Windows is -- stable application interfaces and frameworks that developers can use and a consistent experience for the end-user. As far as price goes, Windows 95 cost around $100 when it came out (which works out to about $140 now) Upgrading XP or Vista to Home Premium will cost less than that, and only $50 more for a brand new install. I don't consider that terribly unreasonable after a decade of Microsoft having to pay fines for including features in an operating system that other operating system vendors are allowed to include without being fined -- and that's not even considering the fact that when people buy new PCs, they're barely paying $100 for the cost of Windows -- especially since that operating system is going to continue to work consistently for the next 5 years, unlike most Linux distributions which will, over the course of that time, have to have applications replaced and reinstalled because some guy in charge of some obscure API quit his project over some hissy-fit and now a critical update which happened to replace that API broke all my apps. $199 just doesn't seem like that much of a deal breaker to me. Over five years, that's $40 year. Most people spend that in a week on Mocha Frapucinnos. No one complained when Leopard was $129, and Apple doesn't even have the expense of R&D to make sure their operating system works with nearly every piece of hardware on Earth. The only way I see anyone being screwed now is that people who purchased Vista Ultimate aren't getting very much of an upgrade deal and they literally got ripped off with Vista Ultimate. *Most incompatibilities between versions of Windows are directly the fault of software and hardware vendors such as Hewlett Packard who specifically make sure there stuff doesn't work in newer versions of the OS in order to sell you a new product.
Well, compared to Microsoft Office 2007, there are a few downsides: 1) It has much less functionality. Now most people don't even use 10% of the functionality available in Microsoft Office, but when you do, you're out of luck. Especially when you open documents that were made in Microsoft Office which use functionality that Open Office doesn't have. 2) It's quite a bit slower to start up and uses more memory. 3) It uses Java for certain functionality, which is unavailable if you don't have Java. Most people don't have Java installed; the market penetration is low. 4) The user interface is outdated; compared to the interface of Office 2007, it is very cluttered. A lot of functionality is not easy to find or reach. It also makes doing simple tasks a lot harder and more time consuming. 5) The user interface is not native. This means that, when on Windows, the program doesn't exactly look, act and behave as you might expect. This frustrates some users. 6) The translations aren't always up to par. Some dialog boxes or descriptions are very confusing. But on the upside, it is free. So if you don't try to open documents made in Microsoft Office, don't care for advanced functionality or easy ways to format and design your documents, there's nothing wrong with it.
Microsoft doesn't bear the cost of testing device drivers - if a hardware vendor wants their driver to be WDM certified they have to pay Microsoft who have always chosen to blame the hardware developers for any computability issues rather than acknowledged any issues with their software. And frankly I'm going to call bullshit in your theory about companies like HP not updating drivers. If that was the case then there would be no support for any older model HPs. Even if they drop support for some of the much older printers (I've just looked through on Windows and the likes of the LaserJet II & III are now longer listed as printers driver shipped with Windows). a) those printers are now over 10 (probably closer to 15) years old and very few would be left in use. b) the age of the printer and the limited numbers wouldn't be worth the costs of putting the drivers into Windows. c) if there is a vista driver for it, it will run with Windows 7.