Microsoft is releasing a new preview version of Windows 10 today, days after a build leaked to the web and nearly two months since the company’s last public update. Microsoft’s big promise of the Windows 10 development has been a focus on delivering regular builds to testers to gather feedback, but the company has struggled to get its latest release out of the door. Despite that, the new release comes less than a week after it was compiled within Microsoft, an impressive speed that's similar to how Xbox updates are delivered.

Disappointingly, this new preview won't include Project Spartan, Microsoft’s Internet Explorer successor. While the software maker had promised the next preview would include a test version of Spartan, that’s not arriving just yet, and it appears the company misspoke. Without Spartan, most of the new additions in today's preview seem like rather minor tweaks and UI changes as Microsoft marches towards its summer release for Windows 10. The Start Menu now has transparency effects, with some tweaks made to improve how apps are displayed and the ability to drag and drop them and organize them. Speaking of drag and drop, the virtual desktops feature — a new addition to Windows 10 — now supports the ability to drag an app to a different desktop. It also means only running windows in a Virtual Desktop are shown on the task bar, reducing some confusion around the new feature.

While Cortana arrived in the previous preview, it was limited to the US. Microsoft is expanding that today to China, the UK, France, Italy, and Spain. "Cortana is still fairly new to the desktop but we are continuing to fix bugs and add new capabilities all the time," explains Microsoft’s Gabe Aul, who manages a Windows Insider program. Microsoft is also tweaking the network UI for connecting to Wi-Fi networks, with improvements to quickly connect to networks. The Photos app is also getting some improvements, including a Live Tile for OneDrive photos, RAW format support, and keyboard shortcuts for navigation.

Microsoft is also improving its stylus support in this latest Windows 10 preview. A new text input canvas is optimized for short text entry, with edit options displayed nearby to easily access with a tap of a pen. Overall, fairly minor additions but a good look at where Windows 10 is heading.

As Microsoft accelerates its testing, Gabe Aul took some time to explain some of the associated delays to The Verge today. The recently leaked build "was a candidate" for this latest public preview, but Aul explains that "there was a set of bugs that we were potentially going to service in that, but we decided to hold for 10041 because it has fixes for those bugs." Discussing the leak, Aul says the company wasn’t happy to see 10036 out in the wild. "With 10036 in particular, because it wasn’t a build we wanted to go externally, it’s not as debuggable as something like 10041. Unfortunately that means the crashes that are being reported on 10036 are not as useful for us to be able to fix the product."

Moving forward, Microsoft will now deliver even more builds to Windows 10 testers, and that means there will be "at the very least a build a month," but the company thinks it will be able to deliver multiple previews per month. There will be periods where Microsoft's various Windows engineers are integrating new features, but for the most part the new Fast ring updates will be delivered in parallel with Microsoft's own Slow ring testing.