Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Joe91

macrumors newbie
Original poster
Jul 16, 2009
22
0
Hello all,

So trying to install Windows 7 on my new Macbook Pro, and having an error: "Your bootable USB drive could not be created. An error occurred while formatting the disk".

I am using a USB formatted as Mac OS journaled, with GUID Partition Table. I have Googled the problem and some reported that unmounting the Windows iso file did the trick, but hasn't worked for me.

I've tried multiple USB drives (some 8GB, some 16GB) and nothing works - I've reformatted them all and still no joy.

Is anyone able to help?

Cheers
 
Does it ask you to specify which .iso file ?

It auto-selects the first .iso it finds, so if you have any other .iso files on your computer, it might be selecting the wrong one
 
You're Restoring a WIndows bootable disc on a Flash drive formatted for Mac Extended (journaled) with a GUID partition table?

Two things that could be wrong (last to first):
  1. The partition table must be MBR.
  2. partition must be formated as MS-DOS (FAT) or ExFAT.
 
Does it ask you to specify which .iso file ?

It auto-selects the first .iso it finds, so if you have any other .iso files on your computer, it might be selecting the wrong one

Yep, when prompted, I always manually direct it to the correct ISO file.

You're Restoring a WIndows bootable disc on a Flash drive formatted for Mac Extended (journaled) with a GUID partition table?

Two things that could be wrong (last to first):
  1. The partition table must be MBR.
  2. partition must be formated as MS-DOS (FAT) or ExFAT.

I watched a video on Youtube where it recommended Mac OS Journaled/GUID Partition table combination. There were no comments suggesting those settings were bad, so I assumed they were the ones to try.

I just formatted one of the USBs to ExFAT with MBR partition table (1 partition), and had the same problem. Hmm.
 
Unfortunately not - should I buy a SuperDrive, burn the iso to a DVD, and try and install via that method?
 
This might be too late to help the OP, but make sure you have not mounted the ISO file. I was having the same exact issue and ejected the iso file and was able to then write the files to the USB drive
 
I was having this same issue, but my ISO was definitely not mounted. It turned out to be an issue with the ISO file, even though it was ripped straight from the DVD. I just downloaded a new file (google "windows 7 iso") and it worked straight away.

w7forums has the iso I used. It seemed like a more legit way than downloading from a torrent, as they are trial ISOs that you just need to register with your valid key upon installation.
 
Does it ask you to specify which .iso file ?

It auto-selects the first .iso it finds, so if you have any other .iso files on your computer, it might be selecting the wrong one
HOLY S*IT! THAT WAS THE PROBLEM! It was selecting the one in downloads folder, but my ISO file was on the dekstop! OMFG! THANKS MAN!
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.