If you buy a new Mac from the Apple store, staffers there (”Geniuses,” as they call themselves) will transfer your files over to the new machine free. This process takes place in the store, though Apple says it generally isn’t a “while you wait” task. If you buy a Mac elsewhere, such as online or at Best Buy (BBY), Apple stores charge $50 for this transfer.

But some people aren’t comfortable with the idea of handing a computer filled with their personal files over to a stranger. If this is the case for you, some other viable options include copying your old PC’s data onto a portable hard drive or onto discs that are compatible with the new computer. If several home computers are networked, files can be transferred onto a drive accessible by all the machines.

This week, I tried yet another method, copying data from a Windows machine over to a new MacBook using a special transfer cable from Belkin International Inc. The aptly named Switch-to-Mac Cable plugs into USB ports on two computers. It came out a month ago and is available for $50 at places like Best Buy and Apple stores. Like other transferring methods, it moves only files and not programs or applications, such as Microsoft Word (MSFT). (Windows applications can run on a Mac using programs like Boot Camp, Fusion or Parallels.)

The Switch-to-Mac Cable makes it easier to transfer data from a Windows PC to a Mac.

I tested the Belkin Switch-to-Mac Cable by transferring data to a new Apple MacBook from my two-year-old Lenovo ThinkPad X60, which runs Vista. (Most people will transfer from an older PC that doesn’t run Vista.)

After installing the software included and connecting the transfer cable to both the Mac and Windows PC, short, on-screen prompts walked me through the steps for copying data from one computer to the other. On one instructional screen, I checked boxes to indicate what I wanted to transfer, including documents, pictures, music, videos, Internet Explorer bookmarks, desktop wallpaper and desktop files. Here, I could also opt to transfer a custom folder as well as personal information from Outlook like email, contacts and calendar.

I liked Belkin’s simple approach, including unintimidating software and a straightforward cable with a glowing, white indicator. But the files didn’t all properly transfer from my Windows laptop to my Mac. Most notably, the software prompted me to move files on my desktop, but the cable moved only five of the 23 selected files stored there.

Also, I use Mozilla’s Firefox as my default browser, but Belkin doesn’t move Firefox bookmarks to the Mac. Still, my Internet Explorer bookmarks moved over into Safari, Apple’s browser. Belkin explained that it left out Firefox transfers, instead focusing on programs like Safari that come installed on Macs. Even without a cable, Firefox itself will export bookmarks to be moved to the Mac in just a few simple steps.

I had no problems transferring everything else, and things like photos and music moved to the Mac appeared there in logical places. For example, photos stored in the “My Pictures” folder on my Windows PC automatically moved over to iPhoto on the Mac and retained their original folder labels in iPhoto.

In most cases, newly transferred files were clearly labeled on the Mac in folders marked “Windows PC.” After my initial transfer, I used the cable for additional transfers, and the data moved in those follow-ups were labeled “Windows PC-2″ and so on. When my email, contacts and calendar transferred from my Windows Live Mail desktop client, I wasn’t sure where this data had moved within Apple Mail because I didn’t see a “Windows PC” folder. A Belkin representative explained that files transferred to Apple Mail are stored in an “Import” folder.

If your transfer doesn’t work perfectly the first time, try moving stray files into a folder that transferred successfully in a previous attempt. I did this with some of my desktop files when they didn’t move over and it worked, albeit with an extra step.

Over the phone, I walked through numerous troubleshooting scenarios with Belkin to figure out why my desktop files didn’t transfer over to the new Mac, but nothing helped. Belkin said it hadn’t seen my desktop transfer problem in its tests.

I was frustrated to find that Belkin doesn’t offer much in the way of detailed instructions for users, such as a FAQs Web site or troubleshooting steps for common hiccups. Its simplicity is an asset, but when performing an important task like transferring data, I’d rather have the option of knowing more than less. Belkin says it plans to add more help for users in the future.

As its name indicates, the Belkin Switch-to-Mac Cable isn’t designed to transfer data from one Mac to another, nor from one Windows PC to another. Nor will it transfer data from a Mac to a Windows PC. Additionally, all hidden directories and system directories are ignored, as are all files with the following extensions: .exe, .com, .dll, .scr, .ini, .db, .lnk.

Not tested was a competing product from Detto Technologies, the $50 Move2Mac, which comes in two versions: One enables transfers from older PCs without USB ports, the other enables transfers from PCs with USB ports that are running Windows 98, Millennium, 2000 or XP — but not Vista, which the Belkin enables.

If you’re moving away from a Windows PC, Belkin’s Switch-to-Mac Cable is one tool that can make this transition easier.

Edited by Walter S. Mossberg

Write to Katherine Boehret at mossbergsolution@wsj.com