Microsoft first introduced its new tabs for each application in Windows 10 last year. While the testers examined them briefly, Microsoft now allows each Windows 10 tester in the Skip Ahead ring to access tabs today with compilation 17618. The biggest addition is the tabs that are now available in File Explorer, a much-requested feature (more than 20,000 votes) and something Microsoft had previously resisted in Windows.
Along with the File Explorer, other traditional Windows built-in applications such as Notepad, Command Prompt and PowerShell also receive support for the tabs. Microsoft is also enabling tabs in the Mail, Calendar, OneNote and MSN News for Windows 10 applications, with the ability to have File Explorer running along with a tabbed version of OneNote or Mail.
Microsoft is testing this feature with Windows Insiders today, and the company has not yet committed to when we will see tabs extensively in Windows 10. It seems that some features of Sets, as Microsoft calls their tabs, will appear in the next update of Windows 10 more go ahead this year. Currently with the code name Redstone 5, this is the first important feature that we have seen appear in the test compilations so far. Microsoft is expected to release new features in Redstone 5 in the course of its development in the coming months.