USB Format


macrumors member
Original poster
Mar 23, 2012
Hi Guys,

I have a 32gb USB drive that is formatted to MS-DOS(FAT) as I want to be able to use it with both mac and window. I use in primarily for college stuff so that I can work on stuff without having to bring my laptop to college. It worked find of the last few year while I was studying for my undergraduate degree, now I go to a different college to study for a postgrad. In the new college when i plug it into the windows computer,s I keep getting told that it needs to be reformatted to work. I've wiped it and reformatted it again to MS-DOS(FAT) but I keeping getting the same issue. It all works fine on the mac

Would any of you have any ideas ?
Help would be much appreciated


macrumors 6502
Jun 25, 2009
Liverpool, UK
You need to format it using Disk Utility and by choosing the drive itself rather than the partition.

Like this:

Screen Shot 2016-10-08 at 1.08.45 PM.png

Screen Shot 2016-10-08 at 1.08.50 PM.png

You see the difference? In the first picture the DRIVE itself is selected, which is the proper way to do it; in the second picture, only the partition is selected, which might not work well for you.