Cannot delete a file on a Windows USB flash drive on a Mac. Locked as “You can only read…” in the Finder
If you are originally from the Windows world, and this USB flash drive was original for Windows use but you are now on a Mac and cannot delete a file off of this USB flash drive, I’m willing to bet that the USB flash drive was formatted in NTFS.
Mac OS X can only natively read NTFS file systems and cannot write to them so you cannot erase the data off of that disk in Mac OS X. So if you want to erase that file, you need to erase it on your Windows machine.
That said, if you need cross platform (Mac OS X and Windows) readability and writability for your USB flash drive, you should consider reformatting it using FAT32 or exFAT in the Mac OS X “Disk Utility.” Should work with Windows XP as long as SP2 has been applied to it, above and Windows Vista as long as SP1 has been applied to it as well as Windows 7 and above.
If having improved NTFS compatibility in Mac OS X is needed, there are a few third-party tools around that can help you setup Mac OS X for NTFS reading and writing. This site has a good rundown which boils down to doing the following:
- Install FUSE for macOS which is the magical key to allow this to all happen.
- Install NTFS-3G which is a component will work with FUSE.
- Install fuse_wait which deals with false-postive error messages caused by timeout issues when mounting NTFS volumes in Mac OS X.
This will get you a USB that works on Windows and OSX. It also fixes any non readable media, and can fix USB's that have been flashed as OS installers.
If you want to keep any files on your USB copy them over to your windows machine.
Now. Open up terminal by hitting command-space and write terminal, hit enter. In terminal write:
diskutil -list
this will show you a list of you storage devices, your USB stick should look something like this /dev/disk2 (external, physical):. basically look for external, physical and the right # of GB to ID your drive. One you know which is your USB drive in terminal write
diskutil eraseDisk free EMPTY /dev/disk2
let it do its thing, and you'll have a non formatted USB drive. I assume at this point you want to format it for use with Windows and OSX. in terminal write
diskutil eraseDisk FAT32 USB64 /dev/disk2
after it's done doing it thing you've got a USB stick that'll work on Windows and Mac OSX. Congratulate yourself. You've crushed it. :)