Read only USB key

Mac OS can read NTFS-formatted drives, but can't write to them. FAT32 is the way to go, but the USB stick (by 'key' I assume you mean that type of unit) should have its own software to reformat with. If you've wiped that out, perhaps it can be downloaded from the mfr's web site.

Another issue is that you may be trying to open the files directly from the stick, which it is recommended that you do not do. Always copy/move the file to your hard drive, modify it there, then move/copy back to the stick if necessary. Many apps (especially Microsoft, but many others) will open any file from removable media as Read Only.

There could also be a problem with the stick, itself. They are more fragile than we would like to think & susceptible to magnetism & electronic interference.

Dual 2GHzG5,1.5GB Mac OS X (10.4.3)

I'm pretty sure your problem has to do with the default USB mounting behavior when encountering invalid USB "mode sense" responses by USB mass storage devices. Windows and Linux will both assume a device is read/write, where OS X assumes it is read-only.

Unfortunately I have not been able to find any documentation on how to change this default behavior. Since my 90 support ran out I haven't been willing to pay $50 to get the answer.

Without wishing to appear flippant, you have checked that the lock is not on?

There is no lock. It works fine with Windows XP, just not OS X.

Hi pyves,

I have a USB drive that works fine between my PowerBook and Windows desktop PC. You didn't specify which version of Windows you are using. If it's XP I'm fairly certain it only allows for NTFS formatting (which as Cyber pointed out is proprietary MS format. When you formatted it FAT32 did you then try and reformat it again with Disk Utility and see if it allows for write access?

Jrsy

If you still haven't had any success you might want to try reformatting the flash drive on the Mac.

Insert the flash drive, launch Disk Utility, select the drive in the left panel, then click the Erase tab. Choose 'MS-DOS File System' from the Volume Format list & proceed from there.

FWIW- I've noticed that both USB Flash Drives I have are FAT 16 (Sandisk Cruzer Titanium 512MB & a 'no-name' 32MB). I have no trouble moving between Win XP & Mac OS X with either one.

Good Luck |:>)