Digital images used in Microsoft's "I'm a PC" advertising campaign were made on a Mac.

Some of the pictures have ended up on Microsoft's PressPass Web site to trumpet its new "I'm a PC" advertising campaign. The files' originating-software stamp shows that they were made using "Adobe Photoshop C3 Macintosh." The images appear to be frames from the television ads that Microsoft will launch later today.

To be fair, not all of the images on the PressPass site were generated on Macs. Most were produced using the Windows version of Adobe Photoshop. Microsoft's campaign is the creation of the Crispin Porter and Bogusky ad agency as part of a $300 million effort to improve Vista's profile.