The most recent build of Longhorn – Microsoft's next version of Windows – has some impressive visual touches, including the kinds of translucent objects found in Apple's OS X, and more powerful ways of finding files.

But it doesn't yet exhibit any breakthroughs in productivity, or promised features such as security improvements and smarter connections to handheld devices.

We tested the 64bit version of the latest code released to developers and have viewed demonstrations of a subsequent build. The first beta of the operating system is due for release this summer.

A desktop theme called Aero is about the only sign of Longhorn’s much-touted new Avalon graphics in our pre-beta. Turning mundane buttons, window frames, title bars and icons into animated, 3D-rendered and sometimes transparent objects, Aero brings the Windows interface to life.

Although the WinFS searchable storage system has been abandoned, Microsoft has taken advantage of file attributes in the NTFS file system already available in Windows XP to make Explorer better at ferreting out documents according to author, camera model (for photographs), or genre or album title (for music files).

The operating system lets you create virtual lists based on these attributes so that, for example, you can see every photo on your PC, regardless of where they are stored and without having to explicitly search for them.

Longhorn will also do a better job of connecting to smartphones, cameras and audio players, improving their integration into Explorer and making file transfers and synchronisation more consistent across device types.

Disappointingly, in spite of planned enhancements such as monitoring of outbound data, protection against malware, a new type of restricted user account and a secure startup scheme to ensure that a PC hasn't been tampered with, Longhorn so far has the same minimal security toolbox as Windows XP with Service Pack 2.