"[37][38] In December 2013, technology writer Mary Jo Foley reported that Microsoft was working on an update to Windows 8 codenamed "Threshold", after a planet in its Halo franchise.

[42][44][45][46] A screenshot of a build identifying itself as "Windows Technical Preview" (numbered 9834) was leaked in September 2014, showing a new virtual desktop system, a notification center, and a new File Explorer icon.

A port of Candy Crush Saga made using the toolkit, which shared much of its code with the iOS version, was demonstrated, alongside the announcement that the King-developed game would be bundled with Windows 10 at launch.

The commercials focused on the tagline "A more human way to do", emphasizing new features and technologies supported by Windows 10 that sought to provide a more "personal" experience to users.

[68][69] The campaign culminated with launch events in thirteen cities on July 29, 2015, which celebrated "the unprecedented role our biggest fans played in the development of Windows 10".

[82][83] In-place upgrades may be rolled back to the device's previous version of Windows, provided that 30 days have not passed since installation, and backup files were not removed using Disk Cleanup.

Via a notification area icon, users could access an application that advertised Windows 10 and the free upgrade offer, check device compatibility, and "reserve" an automatic download of the operating system upon its release.

Universal apps can be designed to run across multiple Microsoft product families with nearly identical code‍—‌including PCs, tablets, smartphones, embedded systems, Xbox One, Surface Hub and Mixed Reality.

Devices with supported cameras (requiring infrared illumination, such as Intel RealSense) allow users to log in with iris or face recognition, similarly to Kinect.

In addition, whereas weak passwords may be broken via rainbow tables, TPM causes the much-simpler Windows PINs to be resilient to brute-force attacks.

[138][134] The enterprise edition of Windows 10 offers additional security features; administrators can set up policies for the automatic encryption of sensitive data, selectively block applications from accessing encrypted data, and enable Device Guard‍—‌a system which allows administrators to enforce a high-security environment by blocking the execution of software that is not digitally signed by a trusted vendor or Microsoft.

Furthermore, the Refresh and Reset functions use runtime system files instead, making a separate recovery partition redundant, allowing patches and updates to remain installed following the operation, and further reducing the amount of space required for Windows 10 by up to 12 GB.

It initially featured a new standards-compliant rendering engine derived from Trident, and also includes annotation tools and integration with other Microsoft platforms present within Windows 10.

[154][155][156] Internet Explorer 11 is maintained on Windows 10 for compatibility purposes, but is deprecated in favor of Edge and, since mid-June 2022, is no longer supported on editions which follow Microsoft's Modern Lifecycle Policy.

[164][165] Previous versions featured Microsoft's intelligent personal assistant Cortana, which was first introduced with Windows Phone 8.1 in 2014, and supports both text and voice input.

[188][189] Unveiled March 2014 at GDC, DirectX 12 aims to provide "console-level efficiency" with "closer to the metal" access to hardware resources, and reduced CPU and graphics driver overhead.

[190][191] Most of the performance improvements are achieved through low-level programming, which allow developers to use resources more efficiently and reduce single-threaded CPU bottlenecking caused by abstraction through higher level APIs.

[217] Microsoft announced an Extended Security Update (ESU) service in December 2023 for Windows 10 devices, lasting until October 2028, on an annual pricing plan.

[268] On December 7, 2016, Microsoft announced that, as part of a partnership with Qualcomm, it planned to introduce support for running Win32 software on ARM architecture with a 32-bit x86 processor emulator, in 2017.

Unlike Windows 8, OEMs are no longer required to make Secure Boot settings user-configurable, meaning that devices may optionally be locked to run only Microsoft-signed operating systems.

[93] Device Guard requires a UEFI system with no third-party certificates loaded, and CPU virtualization extensions (including SLAT and IOMMU) enabled in firmware.

Unlike Windows 8, OEMs are no longer required to make Secure Boot settings user-configurable, meaning that devices may optionally be locked to run only Microsoft-signed operating systems.

[93] Device Guard requires a UEFI system with no third-party certificates loaded, and CPU virtualization extensions (including SLAT and IOMMU) enabled in firmware.

Cortana's always-on voice detection was considered to be its "true strength", also citing its query capabilities and personalization features, but noting that it was not as pre-emptive as Google Now.

"[342] Concerns were raised that because of these changes, users would be unable to skip the automatic installation of updates that are faulty or cause issues with certain system configurations—although build upgrades will also be subject to public beta testing via Windows Insider program.

"[373] On January 21, 2016, Microsoft was sued in small claims court by a user whose computer had attempted to upgrade to Windows 10 without her consent shortly after the release of the operating system.

[386][387] Despite this, some torrent trackers announced plans to block Windows 10 users, also arguing that the operating system could send information to anti-piracy groups that are affiliated with Microsoft.

[388] Writing about these allegations, Ed Bott of ZDNet compared Microsoft's privacy policy to Apple's and Google's and concluded that he "[did not] see anything that looks remotely like Big Brother.

"[384] Columnist Kim Komando argued that "Microsoft might in the future run scans and disable software or hardware it sees as a security threat", consistent with the Windows 10 update policy.

In late-July 2020, Windows Defender began to classify modifications of the hosts file that block Microsoft telemetry servers as being a severe security risk.