Windows 10 Technical Preview is a work in progress, and Microsoft began sending Build 9860 to enthusiasts and developers on Tuesday. The new code's estimated 7,000 changes include a much-anticipated notifications function, as part of a new Action Center.

Users who've already downloaded the Windows 10 Technical Preview may check for new preview builds as part of the “Update and Recovery” option. The download totals between 2GB and 2.74GB, depending on CPU architecture and language, Microsoft said.

After installing, your PC will reboot and begin the provisioning process again, asking you for your Microsoft account. In other words, don’t have anything stored on that PC or partition that you’re not prepared to lose.

“Sometimes they’ll be more frequent and sometimes there will be longer gaps, but they will always be chock full of changes and improvements, as well as some bugs and things that are not quite done,” Gabriel Aul, the engineering general manager for the Operating Systems Group at Microsoft, wrote of the new builds. “As we’ve said, we’re sharing stuff early and moving quickly to do so. In fact, the build that we’re rolling out today is something that we ourselves only got a little over a week ago!”

Of the 7,000 or so changes to the code between the older 9481 build and the new version, some of them are in response to suggestions made by users as part of the Windows Insider Program.

The most important addition is notifications, which had been rumored to be an eventual part of Windows 10. In Windows 10, notifications will be part of the Action Center, Aul said, which will be accessible from an icon in the lower right corner of the taskbar, next to the date and time.

“You’ll see notifications from the system and apps—from new emails and invites to IMs, Facebook posts and more—all in one place, so you don’t miss a thing,” Aul wrote. Quick actions and a cleaner user interface will come later, he said.