Microsoft Corp. CEO Steve Ballmer offered a glimmer of hope on Thursday to fans of the company's XP operating system, saying the company may reconsider its decision to stop selling XP soon.

But Ballmer was adamant that "most people who buy PCs today buy them with Vista."

"That's the statistical truth," he told reporters at a news conference at Louvain-La-Neuve University. "If customer feedback varies, we can always wake up smarter."

Fans of the six-year-old operating system set to be pulled off store shelves by June 30 have plastered the Internet with blog posts, cartoons and petitions recently. They trumpet its superiority to Windows Vista, Microsoft's latest PC operating system, whose consumer launch in January was greeted with lukewarm reviews.

Ballmer said the customers buying PCs with XP are IT departments who are having trouble shifting old machines to newer technology.

Some 160,000 people already have signed an online Save XP Web petition who want Microsoft to keep selling it until the next version of Windows is released, currently targeted for 2010.