Five months ago, Apple Computer Inc. launched its "Switch" advertising campaign, designed to lure Windows users over to Macs. It features real-life PC users, ranging from students to information-technology professionals, voicing frustrations with Windows that drove them to the Mac.

With only 5 percent of the market, Apple's $117 million campaign takes direct aim at the 95 percent of computer owners who use some version of Microsoft Corp.'s Windows.

Apple has set aside a substantial section of its Web site not just to convince Windows users that the Mac is better, but to ease concerns about the process. An entire page is devoted to such questions as "How will I get and send e-mail?" and "Can I run a Mac on a PC network?"

A cynic might question just how many "switchers" actually exist. The only statistic Apple would disclose was that in the month after the television campaign began, it had 1.6 million unique visitors to its Switch Web page, 60 percent of them from a Windows machine.

Nevertheless, switchers weren't hard to find one recent Saturday at the Apple Store in Towson Town Center.

Randy Cox, a computer programmer with Northeastern Supply Corp. who specializes in Microsoft's .Net Web services, was looking to buy his first Mac, an iBook.

Cox said Apple's Switch ads had caught his attention, and as a programmer, he was intrigued by Mac OS X's Unix underpinnings. Unix is the umbrella name for a family of computer operating systems renowned for their versatility and stability.

"I want an iBook for my personal use, to play with Unix," Cox said, noting that he's also impressed by Mac OS X's sleek look and feel.

According to Apple, about 40 percent of the people visiting its 50-odd Apple Stores nationwide are Windows users or first-time buyers.

Darcy Plante, a Towson resident who teaches biology at C. Milton Wright High School in Harford County, returned to the Apple Store to obtain a missing power adapter for her new iBook, purchased two days earlier.

A PC user "all my life" -- she's 21 -- Plante said that she liked Apple's multimedia software like iPhoto and iMovie, and that Apple makes both the hardware and software, reducing the potential for conflicts.

Of course, tempting PC users to try a Mac is only half the battle. For those who have used Windows for years, moving to a computer with an unfamiliar operating system raises many concerns.

One of the first hurdles facing a switcher is getting their PC data transferred to a Mac.

Apple's "Guide to Switching" on its Web site describes how to transfer data manually, but the company also knew many that would prefer an easier, more automated method.

So it enlisted a company called Detto Technologies Inc. of Bellevue, Wash., which already had a product for moving data from an old Windows PC to a new one, to develop software that would move data from a PC to a Mac.

Detto's $59.95 Move2Mac software, released Nov. 11, consists of a USB cable to connect the computers and software for both machines. The PC program collects data specified by the user -- documents, photos, music and databases, including addresses in Outlook Express and Quicken files.

The Mac program takes the incoming PC data and deposits in the appropriate Mac OS X locations.

Move2Mac can transfer 500 megabytes of files in 15 minutes, and those who have tried it say it works as advertised.

No matter how the PC files get to the Mac, however, a switcher faces still another problem: Will they work?

Move2Mac doesn't solve this problem, which can get dicey. Some files, like JPEG images and Adobe Acrobat (PDF) files, are universal. And Microsoft's Macintosh Business Unit has done a great job of ensuring that files created with the PC version of Office open in the Mac version, and vice versa.

But if you use a Windows program that has no Mac version, and doesn't save files in some sort of generic format (like plain text for word-processing), your best hope is translator software.

Two excellent translator programs are Thorsten Lemke's legendary Graphic Converter, a $30 shareware application that can read almost every graphic format ever devised; and DataViz's $100 MacLinkPlus, which can convert many word-processing, database and spreadsheet files -- including Microsoft Office documents.

Another option for Office documents is the $50 ThinkFree Office.

If all else fails, or you absolutely need a Windows-only program, there's always Virtual PC, a $200 program from Connectix that allows you to run any version of Windows you prefer, from Windows 95 up through XP, on top of the Mac OS.

While the emulated Windows environment is much slower than a real PC, with the speed depending on the version of Windows ("newer" means "slower") and the hardware in your Mac (the faster the processor and more memory, the better), Virtual PC can be a godsend. It won't run fancy 3D games, but runs most Windows programs flawlessly.

Better than emulating a Windows program is finding a Mac alternative.

Jack Suess, the Chief Information Officer of the Information Technology Office at the University of Maryland, Baltimore County, found that when he switched 11 months ago, some of his Windows software wasn't available for the Mac, but he soon found equivalent programs just as good or better.

"The biggest challenge was getting the various software tools I use over to the Mac," Suess said, noting that "there are some great applications for the Mac."

For example, Suess discovered that Microsoft's Visio diagramming and charting program has no Mac version.

His replacement: OmniGraffle, from Omni Development Inc. of Seattle, Wash., a company that specializes in Mac OS X software.

The average switcher, however, probably won't need to replace many programs. Mac OS X versions of America Online Inc.'s software, Quicken's financial-management software and, of course, Microsoft Office all exist.

Aside from compatibility issues, switchers may also need to learn how to use the Mac OS. Although not radically different from Windows, there are enough discrepancies to create potential trouble for PC users.

"We were so used to the sometimes-difficult way of doing things under [Windows 98] that we couldn't figure out how to use a similar Mac app!" said Glen Richards, a Fort Meade native who maintains a Web site for vintage jazz recordings from his home in Dallas, Texas. Richards and his wife, Selah, replaced their Windows desktop with an iBook in January.

Richards said his Windows habits tripped him up with iPhoto. "I couldn't find the menu option to move certain images," he said. "The answer: just drag 'em – way too simple!" Switchers adjusting to the Mac's operating system have many places to turn for help.

The Apple Stores offer weekly training classes on the Mac OS, as well as on Apple's multimedia software, like iMovie; several books on using Mac OS X are available, including David Pogue's Mac OS X: The Missing Manual, 2nd Edition; and Web sites like OS X FAQ.

Based on his experience, Richards advises switching.

"It's great to use a solid, dependable and secure operating system without flaky license agreements and restrictions on installations," he said.

"Do it," added Selah Richards. "Using your computer can be fun again."