Most recently, I was using a 4GB USB stick drive to copy files from a PC laptop when the laptop went into hibernation (ran out of batteries).
When it came back to life, the drive wouldn't read on the Mac I wanted to copy the files to.
I thought I'd reformat it on the Mac OS machine I have and used Disk Utility to format it as FAT32 format which should mount on a PC. It showed 4GB on my Mac but when I put it in a PC it said it needed to be formatted and would only offer to format it as 200MB. Needless to say, I was slightly"miffed".
I had a sneaking suspicion it was to do with the GUID partitioning scheme newer Macs use for disks. Some Googling later, I came upon this post by MacTalk Australia forums user Oceanic:
http://forums.mactalk.com.au/28/75333-formatting-usb-drive-mac-windows.html#post937734
which had the answer:
I have managed to do it using Disk Utility.This worked fine and I now have a perfectly functioning PC formatted drive (Apple don't make it easy!). I've reposted it here as I spent considerable time Googling the answer and hopefully if I type enough in it will help someone else.
- Select the drive, then go to the partition section.
- Select the format as MS-DOS (FAT) (it will make this FAT32).
- Select the number of partitions (I have always selected one) in the drop-down box.
- Click on the Options button at the bottom of the partition diagram.
- Select the Master Boot Record option.
If you now apply that, it should create the drive using MBR (master boot record) rather than GUID Partition Table (GPT). Windows is incapable of reading GPT when created on a Mac. If you don't select an option, it seems to use GPT as the default, thereby rendering the drive unreadable on a Windows machine.
I'm guessing this also would have fixed another USB drive I'd bought. It was one with 2 partitions - one for security - which I didn't want. I tried to do it as 1 and it all went wrong. This may have fixed that too.
