If you regularly use a USB stick and switch between Mac and Windows, you will run into the limitation that you can only use the stick for one system. We show you how to format a USB stick for both platforms.
Format USB stick for Mac
If you have a USB stick that was previously used on a Windows machine, you can use the OS X Disk Utility to prepare it for use on your Mac. To do this, go to ‘Applications> Utilities> Disk Utility’. Then select the USB stick, click ‘Delete’ and enter a different name in the window that follows. At ‘Structure’, choose ‘Mac OS Extended (journaled)’ and click on ‘Delete’. After a few seconds or minutes, depending on the size of the USB stick, it is ready for use with your Mac.
Format USB stick for Mac and Windows
For users who are permanently switching from Windows to Mac, it is sufficient to follow the steps above. However, if you switch between platforms more often, it is smarter to format the USB stick for both Mac and Windows. Again, go to ‘Applications> Utilities> Disk Utility’, select the USB stick and choose ‘Partition’. Make sure that one partition is created, choose a name and for Structure select ‘ExFAT’.
Confirm your choice with ‘Apply’ and wait for the process to complete. You can then use the USB stick for both OS X and Windows, although the FAT file system has the limitation that you cannot use files larger than 4GB. You may also need to format the USB stick in Windows when using it for the first time. That takes a few seconds at most.
A common problem is that after formatting by OS X, the USB stick appears on Windows with only 200MB of available space. If your USB stick has a larger capacity, you can reformat it with a program like HP USB Disk Storage Format Tool. Then you can use the (full) volume without any problems on both Mac and Windows.