Burn ISO to USB or external HD with Disk Utility

I am desperately trying to burn a ISO file to a USB and external HD but Disk Utility does not want to. Instead I get the error message "Could not validate source - error 254". So there must be a problem with the source which is the ISO file.
I already tried setting the Partition Map Scheme to both Master Boot Record and GUID Partition Table. I also formatted the drive to FAT and HFS+. I cannot find the cause of this error. It clearly looks like Disk Utility does not like burning ISOs to USBs or HDs.
However, I really really need to this since I cannot burn ISOs with my SuperDrive which is also a common problem ( http://discussions.apple.com/thread.jspa?threadID=1918925&start=0&tstart=0 ) with my MacBook Pro.
I am 100% sure the ISO file is fine. Also checked the SHA-1 and everything else is fine. I should also mention that the ISO file is the Windows 7 RC. So yeah..this time it's not Windows' fault.
I just need a way to install Windows without using the optical drive. I don't even want to think about what I will do when Snow Leopard comes out...

Frankly, I don't. I had windows installed before but I deleted the partition already. and I wonder why I deleted the backups of it (created with Winclone)...BIG mistake

valen333 said:

Disk images, even iso images; come in a few different formats. I was able to use a free program called DMGConverter ( http://sunsky3s.s41.xrea.com/dmgconverter/download.html ) to convert my iso to Mac OS Extended/ISO (Joilet) Hybrid Images. Disc Utility finally stopped complaining and I was able to restore the new iso successfully to my external usb hard drive.

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Thanks for the tip! Better late than never. I hope this will help me in the future.

richthomas said:

have you tried to restore the ISO image to your USB disk?

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Yes I did. The problem was that Disk Utility doesn't like ISO files.

DoFoT9 said:

lol if you say so. i have 100% compatibility with iso files......

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You can burn them on an external hard drive or USB?

DoFoT9 said:

no, how could i possibly burn an iso file to a usb hard drive??

i can, however restore the iso to an external disc.....

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Have you ever tried restoring a Windows installation disc?

DoFoT9 said:

no i have not, im simply thinking logically from my experiences with many many other ISO files (many of which are osx system iso files etc).

i am confused why you are trying to restore it to a HDD partition.. seems a little odd.

vista -> cannot be installed onto external HDDs, maybe the iso cant either?

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Maybe it is because of the Windows ISOs I have used.

I was trying to restore a Windows 7 RC ISO to a USB and to my external FireWire so I could boot from there and install it on a Boot Camp partition since my Superdrive did not work (and I didn't have a blank dvd).

DoFoT9 said:

could be, i have the win7 RC. i can give it a go in a day or two and get back to you if you wish.

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No that's ok, thanks! I really appreciate your help
This thread was dead for a month or so. In that time I fixed my SuperDrive and bought blank DVDs. I just bought a can with compressed air and cleaned my SuperDrive with it. It worked fine after that. It used to eject every disc I inserted after spinning the disc for a few times.

DoFoT9 said:

fair enough, i understand as my super drive is dead! you could also try installing to the bootcamp partition by booting from the actual image stored on a HD - there is a thread going around here how to do it - not sure on the success rate though..

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I heard of that. Well, now that I don't have that problem anymore I won't need it.
Can't believe that Windows can cause trouble when not even installed...

DoFoT9 said:

my superdrive has exactly the same symptoms to yours, maybe all it needs it a can of air.. i might try it.

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Yeah I was desperate to get it working. I never use my SuperDrive but on very rare occasions I do need it.
There was a big thread on the Apple Discussion Forum about this and someone mentioned that he/she just cleaned it compressed air. So thats what I did and it working fine now

Hope it works for you too! And thanks again for your help!

ChazUK said:

How about this. (it's a bit long winded but may work)

Install Windows 7 RC to a Virtualbox VM (no need to use your key as it is a temporary installation) using the iso.
Install Daemon tools lite and copy the iso file to your Virtual box vm.
Put your usb drive in and mount it on the virtual machine.
Use a standard Windows guide to create a usb bootable drive for Windows 7.

Bit of a PITA but it may help.

EDIT I see you fixed it.... OOPS!

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^^ thanks though. I might need this in the future

DoFoT9 said:

i have an external FW optical drive so im not really that bothered by it i guess, my optical drive isnt even in the computer atm lol im trying to put another HDD into it! haha thanks but ill give it a go. any particular areas to hit?

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I would have bought en external optical drive too if my SuperDrive wouldn't have started working again. Glad I didn't have to spend the money.

I thought about the same ^^ (building a HDD into it and remove the SuperDrive) but I never knew where to start.

I didn't really look for any particular areas (because I wasn't able to see anything). I just let the compressed air do its job