Formats

• For Mac computers, you have two choices of formatting for a thumb drive: FAT32 and HFS+, also called Mac OS X Extended. FAT32 was implemented with Windows 95; HFS+ was released with Mac OS 8.1. Most thumb drives come formatted as FAT32. While some claim that HFS+ is faster for data transfers, both file systems perform equally fast.
  
  

FAT32 or HFS+

• FAT32 can be read and written to by either PC or Mac computers, so a thumb drive formatted as FAT32 can be used on either computer. HFS+ , however, can only be written to only by Apple computers, and only Apple computers running windows with Boot Camp and Mac operating system OS X 10.6 can read HFS+ partitions. If you plan to use your thumb drive only on Apple computers, HFS+ is a safe choice. But if your drive will be used with both Apple and PC computers or if you boot Windows on your Mac, choose FAT32. When in doubt, select FAT32, since that format can be used by any computer.
  
  

Formatting a Thumb Drive

• First, back up any data on the thumb drive, since formatting will erase everything on the thumb drive. To format a thumb drive, plug the thumb drive into a USB port. In the Utilities folder in Applications, open Disk Utility. From the list of devices on the left side, select the thumb drive. Click “Erase” and select the format type from the Volume Format menu.
  
  

Troubleshooting

• If the thumb drive doesn't mount, try plugging it into a different USB port. For instance, the port on Apple keyboards isn't powered, and some thumb drives require a powered port. If switching USB ports doesn't work, mount the thumb drive on another computer. If the thumb drive doesn't mount on any computer, it is dead.