Windows 10 May 2020 Update, also known as 20H1, is expected to start rolling out from May 26 through May 28. The second update of Windows 10 in 2020 may be a minor affair, and it will not bring any significant improvements or new features. Another low-key upgrade, similar to the November 2019 update released in the second half of 2019, would be this.

Microsoft has not yet confirmed this, but a company blog post has released details of upcoming changes to the Windows 10.

The next real feature update will debut in the first half of next year after May 2020 Update, and will be codenamed Windows 10 21H1 or Iron (Fe).Microsoft unintentionally reported in a blog post for Windows Subsystem for Linux that the next feature update is codenamed "Iron," and will be moved to the development branch (Fast Ring) in June.

Insider builds currently come from the "mn release" branch. The 'mn' stands for Manganese, which is an ingredient in the periodic table, and also for Windows 10 20H2 's internal codename, the next minor feature update arriving later this year.

Next after Manganese (20H2) is Iron, which is Windows 10 's internal codename 21H1. Microsoft said in a WSL blog post that the Windows 10 21H1 preview builds will start rolling out to Fast Ring testers in June.

“The Fast ring is currently on our Manganese (Mn) OS branch. We expect the Fast ring to switch over to our Iron (Fe) branch toward the later part of June which will expose this new functionality to Insiders,” Microsoft noted in a now-edited blog post, which we noticed today after a user tipped us.

The blog post also confirmed that Fast Ring Windows Insiders are currently testing Windows 10 20H2 (Manganese) update, which would mean that any new improvements could be introduced until June this year.
Windows 10 21H1, also known as Windows 10 Iron ( Fe), will be the first major update in 2021 and could come with upgrades to the Start menu, which Panos Panay recently teased.

Microsoft has teased a new Windows Start menu in a Windows Insider podcast that de-emphasizes the colorful Live Tiles for a more simple-looking icon interface.

Unlike the current Start menu, the new layout offers a more unified background colour in both dark and light modes and app colour does not dominate the background colour.

With Windows 10 version 2004 nearly ready for public launch and the second '20H2′ update planned to be a minor upgrade, it was reported that cosmetic improvements to the Start menu will not make it to the general public until 2021.

However, sometime later this year, possibly with Windows 10 21H1, the Start menu changes could make it to the Preview build.