Microsoft’s latest preview of Windows 10 may add a blast from the past: Aero Glass, the beloved transparency feature that originated in Windows 7. In addition, Cortana has been more tightly integrated, and the Continuum exprience has been improved, Microsoft said.

The new build will be available to subscribers in both the “fast” and “slow” rings, meaning there will be ISO files to download for those who want to start fresh. Also, Microsoft has stopped calling them “technical previews” and now refers to them as ‘Insider previews.”

Like build 10061 that came before it, the new build 10074 of Windows 10 polishes the user interface. Live Tiles will use a 3D animation when flipping, for example.

Here's where Aero Glass might come in: In his blog post, Gabe Aul, who has overseen the rollout of the Windows 10 builds, said there’s a 50 percent chance that your Start menu of the new build will include the Aero Glass transparency, giving it the appearance of “frosted glass.” (See an example of Aero Glass in the top image.) Microsoft's doing some a/b testing on this, trying to figure out which approach is best for users.

Why this matters: As Microsoft moves forward to Windows 10, more users are beginning to wonder what it's going to look like, as well as what it will actually do. Remember, one of the reasons consumers soured on Windows 8 was because of the Start menu. This is a subtly important build for Microsoft.

Cortana gets an upgrade

Cortana has also received a makeover. According to Microsoft, the visual appearance of the digital assistant has been more closely integrated into the Start menu, replacing the Search function. Cortana also now displays in a split-rail view, breaking out the Notebook or Reminders into a separate window.

Cortana’s gotten smarter, too. Check out the new questions that you can ask her—which she’ll attempt to autocomplete as you type.

Weather – “Seattle Weather”

Finance – “MSFT stock”

Dictionary – “define astounding”

Calculator – “48*92”

Flight Status – “UA 238”

Reference – “how tall is brad pitt”

Showtimes – “movies near me”

Tech Help – “memory in my computer”

Time Zone – “time in London”

Unit Conversion – “42 ft in meters”

Chit Chat – “tell me a joke”

Microsoft’s app recommendations are now live, Aul added. In Microsoft’s Build keynote Wednesday morning, company executives showed off how Cortana and the Windows 10 lock screen will suggest apps for you to try out. For example, if you’ve never picked up the stylus on the Surface Pro 3, Windows will suggest you try out Fresh Paint.

Other improvements include:

Music and Video app updates: you can now rent and download movies, and the new Music app received some visual improvements.

Xbox app update: If you haven’t already received the update, the new version adds Game DVR for PC games, screenshots, a Live Tile, user profiles, and real-name sharing.

Windows Store: Although the single unified Windows Store isn’t yet available, the app has been improved to show Xbox Live games as working, and in-app purchases, too. Apps you purchased on a PC running Windows 8.1 will now show up in the Store Beta on Windows 10 as owned (and vice versa), Microsoft said.

As always with each preview, there are some things that don't work: The People app remains broken, and you won’t be able to run games in full-screen mode. But time marches on, and Windows 10 continues to mature.

Clarification: Microsoft said that there's a 50 percent chance that any download of the new build will receive the Aero Glass transparency feature.