Windows 10 build 17666 releases with new features

In the latest Redstone 5 preview, Windows 10 (version 1809) gets new cloud-powered clipboard, Your Phone app, dark theme for File Explorer, Sets improvements, and much more.

Windows 10 build 17666
Windows 10 build 17666

Microsoft is now rolling out Windows 10 build 17666 for PCs enrolled in the Fast ring as well as for devices using the Skip Ahead option. This new release, which is part of the Redstone 5 development, brings a number of noticeable improvements and some big features.

Windows 10 build 1766, according to the company, introduces a new clipboard experience, improves Sets with Fluent Design and other tweaks, and File Explorer gets a dark theme. In addition, with build 17666, Microsoft is also introducing the new “Your Phone” app, Notepad gets updates with new features, you can now rename folder tiles, and a lot more.

What’s new with Windows 10 build 17666


Starting with this flight, Windows 10 introduces an update version of Sets uses the Acrylic element, part of Fluent Design, in the title bar, and the window border are now grey.

You can now use the Alt + Tab keyboard shortcut to switch back to recent tabs from Microsoft Edge, and not just the active one.

Sets on Windows 10 build 1766
Sets on Windows 10 build 1766

If you prefer the Alt + Tab shortcut to switch between apps only, then you can always go back to the old way enabling the “Pressing Alt + Tab shows the recently used…” setting in Multitasking Settings.

Windows 10 build 17666 also introduces the ability to decide whether apps and websites should open in a new window or a new tab. In the Sets section of Multitasking Settings now allows you to set your windowing preference.

If you choose “Window,” new windows won’t open into a new tab unless you explicitly click the plus (+) button or drag with your mouse. Choosing “Tab” opens any new windows invoked from your running apps into tabs.

You can also mute web tabs when using Sets. Simply click volume icon on the tab and the audio will mute.

In addition, sets of tabs will open in the background and use no resources until you go to the tab, which translate in better performance restoring a bunch of tabs.

Even further, Task Manager has now been added by default to the list of apps were not to enable Sets.


In Windows 10 version 1809, Microsoft is also planning to introduce a new clipboard experience that leverages the cloud to copy and paste things across devices, and starting with build 17666, we’re getting a preview of the new experience.

The experience works just like before, using the Ctrl + C to copy and Ctrl + V to paste, but now there is a new experience that you can open using the Windows key + V keyboard shortcut that allows you to see your clipboard history.

Clipboard on Windows 10 build 1766
Clipboard on Windows 10 build 1766

Using the new experience, you can also paste anything that is listed in the history, and you can pin items for things you paste all the time.

According to the company, the history roams using the same technology for Timeline and Sets, which means you can access your clipboard across any Windows 10 device.

The new clipboard also brings a new settings page in the System section that allows you to customize many aspects of the experience.

Your Phone

Windows 10 is also gaining a new app called “Your Phone,” which is new way to connect your phone to your PC with Windows 10 that enables instant access to text messages, photos, and notifications.

However, in this flight, you can only link your phone to your PC, and send links instantly to your PC to pick up where you left off, but over time, you’ll see more functionalities.

File Explorer

In this Redstone 5 preview, Windows 10 introduces a new dark theme for File Explorer and context menu that you can enable using the “Colors” page in the Personalization section of the Settings app.

File Explorer with dark theme on Windows 10 build 1766
File Explorer with dark theme on Windows 10 build 1766


After many years, Notepad is getting an update to support Unix/Linux line endings (LF) and Macintosh line endings (CR).

If you need to research a word in Notepad, you can now select the text, click Edit, and use the new Search with Bing option.

Search previews

Up until now, preview in search you do from the Start menu only include preview for search results, but now, preview is expanding to apps, documents, and more.

Search preview on Windows 10 build 1766
Search preview on Windows 10 build 1766

According to Microsoft, the new search preview will help you to get back to recent documents, quickly start new tasks, disambiguate between files by seeing more info, and access quick answers from the web.

In addition, the search experience wider allowing you to access information and actions in the preview a lot faster.

Additional improvements

Along with the new features and improvements, build 17666 also includes a few other smaller changes, including the ability to name your tile folders in the Start menu. The This PC design has been updated so that there’s no longer space displayed for the cloud files state icon. And the snipping toolbar (with Windows key + Shift + S) will now follow your desired theme, light or dark.

Finally, in this flight, the “Have a question” section in the right pane of a page in the Settings app will now surface most common questions about the settings available in the page you’re located using Bing. Also, clicking the question will give a Bing answer in your web browser.

Microsoft is listing the complete set of improvements, fixes, and known issues for Windows 10 Insider Preview build 17666 at the Windows Blog. In case you missed it, you can read all the changes for Windows 10 build 17661 in this article.

Downloading Windows 10 build 17666

Although there are no ISO files for Windows 10 build 17666, the update is available immediately through the Fast ring and Skip Ahead for PCs. This preview build will download and install automatically on your device, but you can always force the update from Settings > Update & security > Windows Update and clicking the Check for updates button.

You can also check out these resources:

About the author

Mauro Huculak is a Windows How-To Expert who started Pureinfotech in 2010 as an independent online publication. He has also been a Windows Central contributor for nearly a decade. Mauro has over 14 years of experience writing comprehensive guides and creating professional videos about Windows and software, including Android and Linux. Before becoming a technology writer, he was an IT administrator for seven years. In total, Mauro has over 20 years of combined experience in technology. Throughout his career, he achieved different professional certifications from Microsoft (MSCA), Cisco (CCNP), VMware (VCP), and CompTIA (A+ and Network+), and he has been recognized as a Microsoft MVP for many years. You can follow him on X (Twitter), YouTube, LinkedIn and Email him at [email protected].