Asking experts about Microsoft's market share will yield a variety of statistics, opinion, and debate. Common sense tells us that specific figures for user base size are accurate and informative. But below the surface of numbers and marketing is a more complex story.
Software sales by Microsoft count three sources: boxed software on merchants' shelves and online stores such as Amazon, installations on computers before sale (referred to as OEM - Original Equipment Manufacturer), and volume sales through vendors. The first two are very inaccurate in determining the number of Microsoft software users. Counting software sold through stores includes boxes sitting on merchant shelves and storage rooms, i.e. sold by Microsoft but unused. Store purchases also don't account for the software a customer is already using. The new software can overwrite the old software or the old software may still be put to use. Sometimes multiple purchases are made because OEM disks are lost, causing a user to be counted twice. The majority of computer vendors who sell their hardware with software installed primarily distribute Microsoft Windows. It's been determined in federal court that Microsoft has used its desktop monopoly to arm-twist vendors into signing contracts requiring their sale of Microsoft software with their hardware. Using hardware vendor sales to count software users proves inaccurate from discounting those who replace the Windows operating system with an alternative such as Linux or FreeBSD after purchase. It also miscounts many corporations which purchase new computers and put older versions of Windows on them.
Statistics also discount those who purchased Microsoft Windows or Microsoft Office but later decided to uninstall it. None of these non-users are subtracted from the software sold by Microsoft when determining user count. Even attempting to account for these sales which don't apply to the size of the user base will prove inaccurate. A very broad survey of home and corporate users would have to be taken. A valid survey would become useless very soon after it's taken because the share of users is likely to be changing quickly.
All of this tends to show Microsoft's user base is smaller than most believe. In addition to the true number of Microsoft users being unknown, market share statistics are even more complicated due to the nature of Microsoft's biggest rivals such as open source software. The nature of open source licenses promotes free sharing, which only surveys can count. Download statistics are often used to assist in determining open source market share, but barely tell more than the basic popularity of Linux distributions and software packages.
License shipment statistics can only be partly used to analyze the server market. Research firms such as IDC routinely ignore anything beyond sales figures. It's simply impossible to account for many scenarios, such as freely downloaded software being used in place of purchased licenses, or purchasing a new Windows license but installing an older version of Windows.
Realizing the facts about Microsoft's actual market share has implications. For corporations making a choice of software development platforms, size of the user base helps determine if something is generally considered useful and if enough knowledgeable developers can be found. Vendors and software developers should look beyond Microsoft. The software industry is alive with more competition than ever.
The tile interface idea for Windows 8 by itself wasn't all that bad; for users with touch laptops and tablets it works just fine, but then Microsoft went a step beyond. They took a nice innovation for touch devices and inexplicably shoved it into the desktop realm. Removing every familiar aspect of the operating system and forcing keyboard and mouse users to work within an architecture that is incredibly unfriendly to the use of a mouse and keyboard was incredibly short-sighted.
Even this, as unnecessarily manipulative Office 365 as it was, would not have been too egregious if they had simply given everyone the choice to start with either the desktop or the tile screen, then business users would at least have been able to move the tile UI out of the way so that they could focus on actual business.
Systems without touch hardware are left struggling because the touch architecture makes the keyboard & mouse highly inefficient, since all of the controls have been broken up into pieces and locations that only make sense for non-touch users if you operate your computer with two mice simultaneously and have a second set of hand available to operate the keyboard.
Making the Windows 8 user experience touch-only proved to be a monumental gaff. It didn't end there, Microsoft compounded that by requiring developers to buy a completely separate license if they wanted their programs to make use of the tile interface at all. Nothing like double-dipping after you've forced software designers into a corner, is there?
In order to make money off that concept, it had to have teeth, locking the tile screen in place was strictly a financial move which solidified that extra revenue stream, forcing all users to get through the tile interface first before they are allowed (temporarily) to use the familiar desktop (without the start button).
So now that we've dispelled the myth that this was merely an idealistic design choice born of aesthetics, we're left with only a few possible motivations: Money, a lack of sound judgment, or a complete disconnect with the people who use their software. Arguments can be made for any of these as factors in the failure of Windows 8, but in truth, upon examination what we find is a mixture of all three.
Removing the start button compounded that mistake by continuing to "remake the computing landscape." All of the familiar management tools, troubleshooting tools and features we have all gotten used to suddenly vanished. Some went to the left side of the touch screen and some went to the right, only coming out if you swipe your mouse/touch to the right of left edge of your screen with nothing visible for the users to cue in on.