Channel Insider content and product recommendations are editorially independent. We may make money when you click on links to our partners. Learn More.

Back when Windows XP was still known by the code name Whistler, the most exciting thing about Microsoft Corp.’s client OS-in-progress was that it wasn’t Windows 9x.

But now that Windows users can take for granted such basics as real multiuser support and relative freedom from blue screens of death, it will take a lot more than making Windows a less-hated part of one’s workday to spur enthusiasm for Longhorn, the code name for Microsoft’s next client OS release.

At the Microsoft Professional Developers Conference in Los Angeles, we got our first look at Longhorn: With its dramatically remade presentation, storage and communications systems, Longhorn should give Windows users and developers plenty to be excited about.

eWEEK Labs tested Build 4051 of Longhorn, which PDC attendees received along with a raft of software preview disks.

We installed Longhorn on a 900MHz Pentium M laptop with 256MB of RAM. Installation seemed to go faster than we’re accustomed to seeing with Windows XP, and we found Longhorn’s partitioning tools more capable and usable than those in XP.

While our test system met the minimum requirements listed on the software’s sleeve—256MB—we recommend testing this build on a system with considerably more RAM. Longhorn is still two years from release, and, at this point, it’s not built for speed. During tests, the hard drive in our test system thrashed almost constantly, swapping data in from its page file.

We found that one of the most interesting aspects of Longhorn is its use of the Windows Future Store, or WinFS, which exists as a layer atop NTFS for enabling SQL-type queries of data on the local file system. This capability is roughly akin to what Be Inc.’s BeOS offered several years ago, and will allow users to perform broad and detailed searches for data on their systems in ways that are not possible in current Windows systems.

Longhorn ships with schemas for ordering certain types of data, such as contacts, documents and pictures, and developers will be able to extend this capability for other sorts of applications and data.

Windows Explorer has been reworked to expose the benefits of WinFS, ordering files by context as well as by location and offering up much more metadata for initial viewing than in Windows XP.

Internet Explorer has a slimmer look now, which reminded us a bit of Apple Computer Inc.’s Safari. Also like Safari, the version of IE included with the Longhorn preview offers pop-up blocking and a download manager, which are both firsts for IE. (The tabbed browsing that distinguishes Safari and Mozilla, among other browsers. remains absent, however.)

Longhorn sports a new look that’s powered by Microsoft’s Avalon, the presentation system that brings hardware-accelerated, vector-based graphics to the standard Windows interface. However, the laptop we tested with didn’t support 3D acceleration, so we weren’t able to put these capabilities fully through their paces.

Microsoft has added a sidebar to the Windows Desktop that works pretty much like the regular Windows taskbar. However, it will also be able to host a variety of interesting applets, such as current headlines from an RSS feed of one’s choice. For now, the most interesting thing that inhabits the sidebar is a big, shiny-looking analog clock.