By Prince McLean

Published: 10:00 AM EST

Apple plans to crank up the anti-Vista rhetoric at its international chain of retail stores later this week, the latest move in a broader bid by the Mac maker to undermine the new operating system release from rival Microsoft Corp.

The campaign, set to get underway this Saturday, will include new store displays and employee t-shirts gently mocking Vista as little more than a washed-up attempt at a modern operating system, those familiar with the matter say.

In a multi-page training manual made available through the company's internal retail system this week, Apple challenged its employees to learn and tout the Mac's many existing advantages over Vista-equipped Windows PCs.

For instance, Apple asks that staffers draw attention to the higher costs and headaches associated with upgrading a PC to Vista, the confusing array of Vista software versions, and the fact that most of the system's features have long been present in the Mac OS X.

At the same time, Apple suggests that retail employees trumpet the Mac's superior digital life style software, its ability to run Windows, and its multi-year head start on Vista.

"Go Beyond Vista," quips one of the t-shirts that Apple store employees will begin wearing this week. The shirts otherwise pay homage to the company's iconic iMac all-in-one desktop computer.

The retail campaign is set to join a similar, multi-national marketing ploy already in place by the Cupertino-based Mac maker. The company's "Get a Mac" campaign, which airs nationally in the US, UK and Japan, has been widely successful in raising public awareness about the Macs advantages over Windows PCs since it debuted in the US last spring.

In the latest "Get a Mac" ad designed to counter last week's roll-out of Windows Vista, Apple pokes fun at the software's burdensome security alert system. Previous spots have focused on the PC's inadequate video conferencing capabilities and the need for most PCs to undergo "major surgery" before upgrading to Vista.