Starting next month, some new PCs could include an unexpected accessory: Windows XP. Microsoft has given PC makers the go-ahead to ship Windows XP as much as one full month before the operating system's official Oct. 25 launch date, sources close to four major PC makers told CNET News.com. Computer makers plan to debut PCs and notebooks with the new operating system in late September, a move that could help jump-start stagnant sales. How soon customers could receive the PCs from the manufacturers is not clear, however, because the testing process could be more complicated for this release of Windows than for its predecessors.

"The industry is hoping to see some kind of upgrade cycle starting with XP," said ARS analyst Toni Duboise. The early release from PC makers "means we could start out the fourth quarter (shipping PCs) with XP; it could only be beneficial."

For Microsoft, the early release of Windows XP has an additional benefit. The company is advancing its release schedule to ship Windows XP ahead of any possible injunction that would delay the new operating system's debut, analysts said.