Microsoft has been developing Windows 7 under a shroud of secrecy worthy of Apple, and it's led to a rash of rumours and unfounded expectations.

So let us state for the record: Windows 7 doesn't have a new kernel, it doesn't run in the cloud and it's not based on Midori (a research project focused on writing an OS in managed code).

In fact, Windows 7 uses the same driver model as Vista – and even refers to itself as version 6.1. We've got our hands on the Milestone Three (M3) pre-beta release of Windows 7, so read on to find out exactly what to expect from Microsoft's newest OS.

Windows 7's philosophy

You can get a good idea about future versions of Windows by looking at the progress of Office under Steven Sinofsky, now Senior Vice President of the Windows and Windows Live engineering group. The changes that he's made to the Windows team aren't just about what new features go into Windows; they're about the whole way that Windows is developed.

These changes are definitely a response to what happened with Vista, which he sees as a learning experience: "As engineers, you have to have some things that don't go as well as you would have liked and you have to go and learn what to prevent. We just really weren't ready when the product [was released]. We did a lot of work, we just didn't do enough and we didn't do the right kind of work, so we had to go and improve that."

The improvements that Sinofsky speaks of are centred within three key areas: the process of developing Windows; the concepts behind 7's key design principles; and the rebuilding of relationships with original equipment manufacturers (OEMs) that were soured by Vista. Culturally, the Windows team is working in a very different way to previous incarnations. Instead of one team creating Tablet PC features, another team working on Media Center features and yet another team working on core Windows pieces (with none of those teams getting together and interoperating correctly at the end), one team now owns an entire feature across all the platforms from start to finish.

The new development process is more structured and more realistic about what can be achieved in three years, and key to this new process is ensuring that every feature included in each of the internal milestones is usable by the end of it. Compare that concept to what happened to the 'three pillars' of Vista. Indigo – the Windows Communication Foundation –does what was promised, but so far it's used mainly by Microsoft's own business applications. The Windows Presentation Foundation that shipped in Vista was ripped out and rewritten at the last minute because it was deemed not to work well enough. And WinFS – the long-awaited Object File System for creating an database of metadata and extensible schemas for different types of data – was shuffled off into SQL Server because Search fulfilled the needs of most users.

Principles for 7

The vision for Windows 7 doesn't sound like a snappy marketing slogan yet. Even Mike Nash, the Vice President for Windows Product Management, doesn't have one. He says: "The things you do today on Windows, Windows 7 makes easier; and the things you always dreamed of doing [are made] possible."