Hours after Microsoft posted a bizarre Web-based advertisement regarding an anonymous Macintosh user who had reportedly switched to Windows XP, the company removed the page amid reports that the information in the ad was fake. But the ex-Mac user, a freelance writer who works for a public relations company hired by the software giant, does exist. And though Microsoft refused to divulge her identity, she says that she really did switch to XP.

"I guess I can tell the truth," says Valerie Mallinson, who works for Wes Rataushk & Associates. "It was me. I made the switch." Valerie was briefly featured in what appears to be a Web-based ad aimed at defusing Apple's popular "Switch" ad campaign, which presents former Windows users who switched to the Mac. But unlike the Apple ads, the Microsoft ad didn't identify Valerie. Perhaps even more confusingly, the photo that accompanied the page wasn't even a picture of Valerie: Instead, it was a stock photo, available for purchase elsewhere on the Internet. After people discovered the ad, and the stock photo, the situation was debated in various online forums. Finally, Microsoft pulled the ad, replacing it with a link to the XP Web site. But the company says everything in the ad is true.

"It was an actual customer," a Microsoft spokesperson said late Monday. "We kind of figured out that really isn't the best way to go about communicating. We decided it was best to point customers to the Windows XP home page."

The switcher ad flap comes just days after a joint Microsoft/Apple announcement regarding a Macintosh/Microsoft Office v. X bundle revived hopes that the two companies were once again working together. Relations between the two companies have been strained in recent days because of Apple's Switch campaign and Microsoft charges that Apple's lack of support for OS X had contributed to slow Office v. X sales.