Windows 10 was officially announced Tuesday, you can now download the preview version!

Keep in mind, like with all testing versions of software, this isn’t for everyone. Windows 10 is going to be buggy, and it’s mostly designed for enthusiasts, developers and business users — in other words: experts. Microsoft recommends installing the update on a secondary machine.

Before you install, as always, be sure to back up everything. This is an early build and will therefore be prone to unexpected crashes, which could result in damaged or deleted files.

If none of that has scared you off, get ready for the return of the Start menu.

There is a before-you-install guide on Windows’ website, plus a section with videos and more tips on what to do once the preview version is on your computer.