As Windows enters its third decade, Bill Gates will tell delegates at the WinHEC 2005 conference later today that the software's computing intelligence will move further towards the edge of the network.

Microsoft's chairman is scheduled to deliver the opening keynote at the annual event for hardware developers, at which he will unveil 64-bit versions of Windows for desktops and servers.

The next decade for the operating system will revolve around Longhorn, slated for release by the end of 2006, and 64-bit computing, Microsoft said.

Windows XP Professional x64 Edition and Windows Server 2003 x64 Edition allow the addressing of 64-bit instruction sets in the latest processors from Intel and AMD.

The operating system will be able to address up to 16TB of virtual memory, a major increase from the 4GB in current versions. It will allow an increase of the system cache from 1GB to 1TB.

Microsoft has predicted that nearly all new desktop PCs will be equipped with 64-bit processors by the end of 2005.

Neil Charney, product manager for the Windows Client Group, told vnunet.com: "We are all going to get 64-bit as we buy new PCs. When Longhorn ships, most people will be buying 64-bit computers."

But the impact on the desktop for now will remain limited, as there are very few software titles that take advantage of 64-bit computing.

And, although the operating system works well with current generation 32-bit software, many computer vendors will keep shipping PCs with the 32-bit version of Windows.

Users switching to 64-bit Windows will need new drivers for peripheral devices such as printers, scanners and digital cameras which may not be available for older hardware. The 64-bit version of Windows will contain only half the number of software drivers that are now bundled with current versions.

The real value for 64-bit is on the server, according to Charney. WinHEC delegates have been told that the "adoption of 64-bit systems is expected to advance rapidly, especially in the enterprise space".

Charney highlighted one example at Microsoft where the time to complete a database query was reduced from eight hours to less than five minutes as a result of the faster access to memory on a 64-bit system.

Microsoft is also expected to release a Longhorn preview to delegates at WinHEC prior to the first beta this summer, and will demonstrate some of the software's visualisation and document organising features.

The company will launch a logo programme dubbed the 'Ready PC' indicating that a system is capable of running Longhorn. The logo tells users prior to the Longhorn launch that a system they buy will allow them to switch once the new software is released.

Qualifying systems require at least 512MB of memory and "anything but the current low end processors", said Charney.

Manufacturers also have to commit to making available a special Longhorn Display Driver Model within 90 days of the launch.