Formatting Flash Drives To Be Read on Windows Machines


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Not sure if this is the exact place to post this, although it does have to do with the Mac OS and Disk Utility. Let me explain.

I am using the latest version of El Capitan, OS 10.11.5, on my late 2012 Mac Mini. I have two USB 3.0 Flash Drives, one 32 gig in size, and the other 64 gig in size. I wish to provide some files to a Windows user friend of mine. So, I went ahead and launched Disk Utility, and Erased and Formatted both drives as ExFAT, with a Master Boot Record as the Partition Map. I subsequently had no problem dragging files to each drive, and some of them were greater than 4 gig in size (thus the ExFAT format). I can mount either drive on each of my Macs, and also on our 65" Samsung Smart TV, and they are read (and processed) just fine.

Earlier today (about an hour ago), I went down to my local Best Buy to see if they would be recognized on a Windows machine. But, they were not! And, this happened no matter which machine I used (Dell, Samsung, Acer, etc.). Each of them had Windows 10 on them. I kept getting some kind of error message (can't exactly remember what it said), and it said to scan the devices. But, I did not know how to do that in Windows, and also did not want to. According to what I read previously, when one formats a device on a Mac as ExFAT, some older Windows and Mac operating systems will not be able to read them. But, such is not the case here.

By the way, I followed the instructions in this link for ExFAT:

http://osxdaily.com/2012/04/22/format-drive-mac-pc-compatible/

I also tried both drives on a Mac at Best Buy, and they were read fine.

So, what am I doing wrong? Also, is there more reliable Mac software that will format devices in a correct, acceptable manner for use on a Windows machine?
 
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I might have found the solution. I did a google search of this issue, and specifically related to Disk Utility in El Capitan, and it looks like the following is what needs to be done:

1. Quit Disk Utility.

2. Launch the Terminal application, and enter the following command (and hit return at the end):

defaults write com.apple.DiskUtility advanced-image-options 1

3. Quit Terminal.

4. Relaunch Disk Utility, and Erase and Format the disk, either as MS-DOS (FAT), or ExFat, and make sure to choose Master Boot Record for the Partition scheme.

I have done exactly this with the 32 gig USB 3.0 Flash Drive, and placed several file son it of various sizes (some of them over 4 gig in size, and thus I chose ExFat as the Formatting choice). I also Erased and Formatted the 64 gig drive the same way, but left it empty.

I hope to go to Best Buy tomorrow and try it. I can mount the 32 gig drive on my Mac and my 65" Samsung Smart TV, and the files are processed fine.
 
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Well, I just back from Best Buy, and it looks like that "fix" worked. After plugging in the 32 gig USB 3.0 Flash Drive into a Windows machine there, I again initially got the "alert"/message about something wrong with the drive. But, when I opened it, it was able to "see" all the files (actually folders containing TV series Episodes). And, it was able to play one of those Episodes (Episode 1 from Season 1 of Fargo). So, it looks like things are good. I did not, though, try to copy/drag one of those folders onto the hard disk and/or desktop on the Windows machine. I am assuming that will be OK.
 
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I just went through a similar thing with a couple of flash drives as I was trying to create an El Capitan virtual machine in Windows 10. Every time I formatted the flash drive to ExFat in the Mac OS it could not be used in Windows and I would get an error message saying it needed to be formatted. Finally discovered two problems that were causing this. One of them OP honestone has already discovered and that is that the partition table type must be manually set to MBR rather than GUID when you format it to ExFat in the Mac OS. By default, the Mac OS formats it in GUID and windows needs MBR for flash drives.

The second thing was that on one of the USB flash drives there was a very small second partition present on the drive of just a few megabytes. Could have been a remnant of some kind when the drive was being used as a restore device for my Windows laptop. Anyway, I had to manually delete the partitions using the Windows diskpart command line tool. When these two problems were corrected the drive could be read both in the Mac OS and in Windows 10.
 
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Thanks for the post, Harry. The MBR format is also needed even if one formats the device as MS-DOS (Fat). I am, though, still a little "leery" as to whether my friend will actually be able to "move"/copy the folders from the Flash Drive to his machine. As I said, when I tried it the second time at Best Buy (after making that change via that Terminal Command), even though I got that "error message", I was able to tap on that message and got a listing of those folders. Tapping on a folder allowed me to select one of the episodes, and I was able to play it on that Windows machine. But, I did nit try and copy any of the actual folders.

I did not do that "tapping" the first time I got that message, so possibly the drive was OK, at least for viewing the episodes. I'm actually thinking of taking the drives to Best Buy and try and Erase and Format them as ExFat via the Windows OS. If anyone can help, how does one do that?
 
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My solution for the 4 gig wall has been to run NTFS for mac on all my macs and format the external whatever (drive, stick, chip etc.) NTFS. Then any pc can read and write to them and so can I.
Only issue is if i want to take files to a mac that's not mine and doesn't have NTFS for mac on it. For this I have externals formatted Mac OS Extended.
 
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Again, my issue is insuring that the formatting via Disk Utility (with the Terminal Command change I used yesterday) will allow these files to be "moved"/copied from the Flash Drive to my friend's Windows machine.
 
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Thanks for the post, Harry. The MBR format is also needed even if one formats the device as MS-DOS (Fat). I am, though, still a little "leery" as to whether my friend will actually be able to "move"/copy the folders from the Flash Drive to his machine. As I said, when I tried it the second time at Best Buy (after making that change via that Terminal Command), even though I got that "error message", I was able to tap on that message and got a listing of those folders. Tapping on a folder allowed me to select one of the episodes, and I was able to play it on that Windows machine. But, I did nit try and copy any of the actual folders.

I did not do that "tapping" the first time I got that message, so possibly the drive was OK, at least for viewing the episodes. I'm actually thinking of taking the drives to Best Buy and try and Erase and Format them as ExFat via the Windows OS. If anyone can help, how does one do that?
Yes, that's what I was trying to say. To use the flash drive in a Windows machine with extfat then you need the partition table to be MBR and not GUID. OS X by default apparently uses GUID.
 
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Yes, that's what I was trying to say. To use the flash drive in a Windows machine with extfat then you need the partition table to be MBR and not GUID. OS X by default apparently uses GUID.
I understand that. As I stated above, after using that Terminal Command to modify Disk Utility, along with formatting it as ExFat, and with a partition scheme of MBR, I still got the same error message, but I was able to get the Windows machine to read the file and play the video I am just unsure if that video folder could have been copied from the Flash Drive.
 
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Well, good news! I went to Best Buy yesterday afternoon to try out the 32 gig Windows ExFAT (with Master Boot Record Partitioning Scheme) formatted Flash Drive. Once again, I got the error message about something being wrong with the drive. I then allowed the Windows 10 OS to scan the drive, and it then offered to "fix" it. I selected that, and it immediately came back and said everything was fine. I then selected one of the video files, and was able to play it. Also, after figuring out the process, I was able to copy one of the folders to the Windows desktop, played one of its video files, and then moved that folder to the Recycle Bin. I then told the OS to remove it from the bin, and it worked as planned.

So, all is good.
 
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