Microsoft plans to release the delayed "x64" versions of Windows XP at the end of April, a company spokeswoman said yesterday.

General availability of the 64-bit products could be announced at Microsoft's annual Windows Hardware Engineering Conference (WinHEC), scheduled to begin April 25 in Seattle. Microsoft will have 64-bit news at the event, the spokeswoman said.

Until now, Microsoft had said the products, which also include a 64-bit version of Windows Server, would ship in the first half of 2005. The products were delayed last year from an end-of 2004 delivery target.

With Windows Server 2003 x64 Editions and Windows XP Professional x64 Edition, Microsoft will provide users with the option of running both 32-bit and 64-bit applications on the same system. The software is designed to run on computers equipped with processors with 64-bit extensions from AMD and Intel.

64-bit systems offer users greater computing power as systems can process more data per clock cycle and can use larger amounts of memory. AMD's Athlon64 and Opteron processors, as well as Intel's Xeon processors, currently support 64-bit extensions. The availability of the operating systems comes long after the processors shipped.

Microsoft released near final test versions, called Release Candidate 2, of Windows Server 2003 x64 Editions and Windows XP Professional x64 Edition early last month. At the same time the company released RC2 of Service Pack 1 for Windows Server 2003. Release Candidate 1 versions of the products were released in December.