Flash memory sticks have generally replaced other forms of removable media such as floppy and zip disks. Available in sizes ranging from 64 MB to 64 GB, flash memory sticks work well for data backup purposes and to transfer data from one computer to another. To share it between a Mac OS X and Windows system, the stick must be formatted with the FAT16 or FAT32 file system. There are different ways to accomplish this, depending on which operating system you're using.
Type "Disk Management" in the "Search" field of Windows Vista/7 and click on the link that appears. Plug the flash memory stick into the system. Right-click it in the Disk Management window and click the "Format" option. Select the FAT32 formatting option for drives larger than 2 GB.
Open a new Finder window in Mac OS X. Run the "Disk Utility" program located in the "Utilities" folder inside the "Applications" folder. Plug the flash memory stick into the computer. Click the flash memory stick in the left side of the window, then click the "Erase" tab. Click "MS-DOS (FAT)" in the "Format" drop-down menu, then click "Erase."
Open "My Computer" in Windows XP after plugging in the flash memory stick. Right-click the memory stick and click the "Format" option. Click the "FAT" or "FAT32" option in the "File System" drop-down menu. Click "Start" to format the memory stick.
Check the flash memory stick before formatting it. Most sticks are preformatted using one of the FAT file systems by the manufacturer.
Reformatting a flash memory stick will delete any data it contains.