[Most recent updates: October 19, 2017]
Windows 10 is now more than two years old. In keeping with the operating system's "Windows as a service" design philosophy, Microsoft has released four major feature updates in that time. That's an unprecedented rate of change, especially if you've grown accustomed to upgrades that arrive every three years or so.
If you have questions about installing (or reinstalling) Windows 10, see this companion post, which is also freshly updated:
FAQ: Installing, reinstalling, upgrading, and activating Windows 10
That post includes advice on how to get a free upgrade, whether you need a product key, and how activation works in Windows 10.
In this post I cover what's included in the latest Windows 10 updates and address some common concerns about how Windows 10 works, including a long-running controversy over privacy.
What is Windows 10?
Windows 10 is the successor to Windows 7 and Windows 8.1. (Yes, they skipped Windows 9.)
What makes this release different from its predecessors? Microsoft calls it "Windows as a service," with the goal of releasing free feature updates twice a year rather than saving those features for major paid upgrades every two or three years, as was the case for the first 25 years.
To underscore this new model, Windows 10 was offered as a free upgrade for its first year on the market.
The first release of Windows 10 to the general public began rolling out on July 29, 2015, and since that date there have been four feature updates (what used to be called upgrades). The most recent feature update was released in October 2017. For details, see "Windows 10 Fall Creators Update: New features to try, but don't rush to install it."
These feature updates have delivered major new features for business customers and have also steadily evolved the Windows 10 user experience.
In early 2016, Microsoft reported 200 million "monthly active devices" running Windows 10. By the end of September 2016, this number had increased to 400 million. As of May 2017, Microsoft says the Windows 10 installed base is 500 million.
Microsoft has publicly backed off its timetable for having 1 billion Windows 10 users by mid-2018, although it still expects to hit that milestone eventually.
How many Windows 10 editions are there?
As with previous releases, Windows 10 is available in multiple editions. All of the editions share some common features, but are sold and distributed differently depending on the type of device for which they're intended and the target market. Business and enterprise customers typically pay more in exchange for access to features that are especially useful in managed environments.
There are three editions of Windows 10 for installation on new PCs. PC manufacturers pay Microsoft for Windows 10 licenses for installation on new PCs. Those costs are passed along to PC buyers.
See also "Windows 10 editions: Everything you need to know."
What are the Enterprise and Education editions?
Windows 10 Enterprise is available only as an upgrade, and only for customers who are part of a Volume License program or who purchase a Windows 10 Enterprise E3 or E5 subscription.
This edition includes all of the features of Windows 10 Pro, along with rights to specialized networking, management, and deployment features that are useful in large organizations. Enterprise-only features include DirectAccess and BranchCache, Device Guard, App Locker, and support for Windows To Go.
Installation media for Windows 10 Enterprise is available through the Volume Licensing Service Center. The Enterprise edition is also available in a time-limited evaluation edition and to anyone with a current MSDN subscription.
The MSDN Subscriptions download page is also where you'll find checked and debug versions for use by developers.
Large educational institutions have their own Volume License option, Windows 10 Education. These customers typically pay much less than their business counterparts, while still getting most of the same features and rights available in Enterprise edition.
A relatively new addition to the Windows Enterprise lineup is a selection of subscription plans like Windows 10 Enterprise E3 and E5, which are available through the Cloud Solution Provider (CSP) program.
Which version of Windows 10 am I running?
The Windows 10 brand might not change, but every feature update has its own version number, and every cumulative update is marked with incremental change in the OS build number.
You can inspect these values on any Windows 10 PC in a variety of ways. Open Settings > System > About, for example, and the list of system details displays values for Version and OS Build that tell you everything you need to know. (You can also use the venerable System Information tool, Msinfo32.exe, or the Version Reporter applet, Winver.exe, to get these details.)
On August 2, 2016, Microsoft released the second major update to Windows 10. Here is what the About page reports for a system running that version with the January 2017 cumulative update installed.
This release, sometimes referred to as the Anniversary Update, is version 1607, with the version number indicating the year and month of release, in yymm format. (This format was first introduced with the November 2015 update, version 1511.)
The major build number (the portion to the left of the dot) is associated with the version. The original release of Windows 10 was identified only by build number, 10240. Version 1511 was build 10586, and version 1607 is build 14393.
The minor portion of the version number, to the right of the dot, identifies the most recent cumulative update that's been installed. For more on how to match version information with updates, see "Windows 10 tip: Find and decode secret version details."
The new versioning scheme is simpler and presumably more comprehensible to nontechnical audiences.
What's new in Windows 10?
See my review, Windows 10: A new beginning for details on the original release. For more on what's in version 1607, see What to expect from the Windows 10 Anniversary Update.
The biggest change is the new Start menu, which completely replaces the Windows 8-style Start screen, as well as the ability to run so-called modern apps in windows on the desktop. Cortana, the voice-powered personal assistant, makes her debut in Windows 10 after an extended run on Windows Phone. Cortana takes over the search box to the right of the Start button after you complete a few quick setup steps.
An Action Center, with notifications and buttons for common system tasks, appears on the right side. It completely replaces the now-defunct Charms menu.
Windows 10 includes a new tablet mode designed to make operation easier on devices that lack a keyboard and mouse. The design shown here, from the original July 2015 release, expands the Start menu to a full screen, although the design is very different from the Windows 8.x Start screen. The hamburger menu (three vertical lines) in the upper left corner shows or hides the menu items on the left side.
Subsequent feature updates have fine-tuned the behavior of Start without changing its core elements.
The list of Windows 10 features also includes biometric support (facial recognition and fingerprint, via a feature called Windows Hello) and a collection of first-party apps: Photos, Mail, Calendar, Groove Music, Movies & TV, and four MSN apps: News, Sports, Money, and Weather.
All Windows 10 devices share a single Windows Store, which offers access to apps that support the Universal Windows Platform. Developers who build these apps can target them to run on devices of many different sizes, from full-size desktop PCs to small tablets and phones. (Yes, Windows 10 Mobile has the same core code used in the desktop version.)
Microsoft Edge has replaced Internet Explorer as the default browser in Windows 10. Beginning with version 1607, it offers support for browser extensions, although six months after the release of that update only about two dozen extensions are available.
Windows 10 version 1511 added support for Windows Update for Business and the Windows Store for Business as well as several other features primarily of interest to IT professionals.
The Creators Update, due in spring 2017, will offer a long list of new features, including improvements to the update engine that should reduce both the size of future updates and the time required to install those updates.
Why is it called Windows 10 instead of Windows 9?
Microsoft's official responses to this question have been almost comically vague. It's reminiscent of the decision to abandon the Metro name, which was also never explained in a satisfactory way .
So we're left to speculate, and my best guess is that choosing the number 9 would imply that Windows 10 is just around the corner, followed by 11, 12, and so on. That's a recipe for delay, as customers play a "watch and wait" game.
One (unlikely) theory speculates that assigning 9 as a version number could wreak havoc with old versions hard-coded to search for Windows 95 or 98 version strings.
It's more likely, though, that the name is about branding. This really is the last big release of Windows, with future updates coming in incremental form. As a brand name to stick with for the long term, Windows 10 is numerologically satisfying, almost ... perfect.
Or, alternatively, there's the "dad humor" explanation: Seven ate nine.
I've been told that Windows 10 spies on me. Is that true?
Like all modern operating systems, Windows 10 uses the internet to provide services, and it collects reports of crashes and installation failures to diagnose problems. It also uses an anonymized ID to track which applications you install and how often you use them.
Collectively, this information is called telemetry, and a Windows 10 component called the Universal Telemetry Client periodically sends this information to Microsoft. The exact amount of information that leaves your system depends on your privacy settings, which can be adjusted to one of three settings, as explained later in this section.
Microsoft says it doesn't collect your personal information (except for the purposes disclosed in its privacy statement), it doesn't scan the files on your hard disk except to index them so you can search locally, and it doesn't have a keylogger.
As part of the "Windows as a Service" model, Microsoft uses Windows 10 telemetry information for product improvement. In addition, Windows 10 integrates online services, such as Cortana and OneDrive, to store and sync personal settings and to build personalized dictionaries using speech and keyboard input.
All of these options can be adjusted using privacy settings in Windows 10. For more details, see:
In 2016, the French National Data Protection Commission found Microsoft's collection of diagnostic information (telemetry) acceptable but said that the default settings for Windows 10 go too far. The complaint singled out Microsoft's practice of collecting information about app usage as "excessive."
A staff member of the Electronic Freedom Foundation, in a signed essay, also criticized Windows 10 for "disregarding user choice" and sending "an unprecedented amount of usage data back to Microsoft...."
In response to those and other criticisms, Microsoft has agreed to make some changes in privacy settings beginning in 2017. Effective with the Creators Update, for example, information about app usage will no longer be sent as part of the telemetry transmissions when you select the Basic level.
For background on the general issue, see the following series of posts:
If you're worried about Windows 10 telemetry, you can open the Privacy tab in Windows 10 Settings, choose Feedback & Diagnostics, and adjust the Diagnostic & Usage Data setting to Basic.
I heard that after a year Microsoft is going to start charging for subscriptions. True?
Not true. Although the Get Windows 10 program has ended, Windows 10 upgrades are still free, if you have an underlying Windows 7 or Windows 8.1 license. And there won't be any surprise fees in the future for those who take advantage of those upgrades.
The basic licensing model for Windows has not changed with Windows 10. You get a perpetual license, with five years of mainstream support and five additional years of extended support. See "Microsoft commits to 10-year support lifecycle for Windows 10" for details.
All Windows 10 devices will continue to receive updates "for the supported lifetime of the device." What does that mean? At some point in the future, it is possible that your hardware will no longer meet the specifications for a new release, and that will be the end of the line. But as long as your device can accept updates, it will get them.
Microsoft contributed to the confusion with some clumsy wording, but its intent is clear. The free upgrade offer was intended to get as many current devices as possible to move to a single platform with a single Windows Store. And the one-year deadline was intended to add some urgency to the decision and to mollify Microsoft's OEM partners, who would rather sell you a new PC than extend the useful life of your current one.
Does Windows 10 really include a keylogger?
Short answer: No. Longer answer here.
More questions? Ask away in the comments below, or visit my bio page and use the comment form (the envelope icon) to send me a note via email.