Boot Camp - Setup was unable to create a new system partition....from Windows install

I removed the extended storage / time capsule, it worked!

I finally solved this issue by moving the USB-drive with Win7-x64 from the right-side to the left-side USB port, and removed the other USB-drive with Apple's "windows support files".

I have a 2012 MacBook Pro 15" +Retina. The guy at the Genius Bar kept telling me this problem was a "Microsoft" problem and nothing is "wrong" with the laptop. But why would the Windows Installer care which drive has the installation drive?

After the error go back one page and do one of the choices below.

Changed from left usb to right usb and it worked.

OR

Changed from right usb to left usb and it worked.

I ran into this problem today with my new MBA 11. Did all of the above to no avail, several times. What fixed the problem for me was to remove the Windows bootable USB drive from the USB port after the first Format attempt failed and got this message (Setup was unable....). Then I ran Format bootcamp partition again with both USB ports vacant. Clicked on NEXT and got an error message, obviously because Windows USB was no longer installed. Pushed the USB drive back in the same port and clicked NEXT again and it worked. So, there is obviously a very strange need here not to have external drives of any kind plugged into any USB ports while completing this step.

After pulling my hair out on this one for a long while, I switched from the microSD adapter I was using to a different adapter (same microSD card though). Worked perfectly on reboot. Not sure what the difference was besides brand, but changing the USB stick could possibly solve your problem.

Same experience on my new Mac Mini (late 2012) / Lion.

Windows 7 installer could not create new system partition until I removed my Time Machine external HDD - then worked fine. 🙂

This helped me, thank's so much!

Tried everything I've read here...still no dice...anyone have anymore ideas???

Thanx!!!

And apparently now I'm really screwed! Tried to back out of the entire process and I have no bootable device! Dafuq!

Well...I just recovered from a minor heart attack! Thanks to apple support and the ol' opt-cmd-p-r trick...http://support.apple.com/kb/PH11243

So for me, I followed all the basic steps, got to the point of where to install windows and stalled out with the 'setup was unable...' hoopla. Tried everything, unplugged, plugged, switched USB sides, made a sandwich, changed sox, put on a hat, backed out, came back in...nothing! Then I said F it and stopped the whole thing...not long after that my heart stopped because when my computer went to restart there was no bootable device! Panicked...started to sweat, got a hold of apple support, did a little finger contortion, and got back to my Mac OS...pshheew!

Was a lil nervous, but I went back to boot camp assistant, started the process again, but I made sure the only thing connected was the ext drive, and that it was connected to the LEFT USB. I first had to remove the Windows partition, and then I created it again.

Followed the same simple steps, and for what ever reason, Windows actually began to load.

Feels like I did a lot of talking to myself, but sometimes that's all we need ;)

Hope this helps! (MacAir 13"/1.8GHz/4GB/128GB Flash_Late 2012_Windows 7 Home Premium OEM_64bit)

when i got the same error, i simply changed my memory stick from right slot to left slot. and clicked try again or clicked back then next again.

that worked for me...

Just got my retina MacBook Pro today, first Mac ever! I spent 5 hours tonight trying to get boot camp to install windows properly. I'm really disappointed, I thought Mac stuff was supposed "to just work", but evidently not. I'm gonna have to have a lot of good times with this notebook before I get over this hair pulling problem I had tonight.

Btw, swapping the CDROM drive from the left port, to the right port finally fixed it for me.

Fix this apple or update your instructions, Jesus Christ!

Just got past this niggle with my first spanking day old iMac.

Like the others I was trying to install with an external hard drive attached. You definitely need to start from the windows partition-forming stage of Bootcamp with NOTHING ATTACHED except your windows usb then see it through following the instructions.

(Also, it's best not to have anything running while you Bootcamp because it will try to restart without prompting you and I managed to cancel the restart by denying it permission through iTunes, leaving me worried that I had broken the format, but it had completed and just needed me to tell it to restart manually.)

Also for those that don't know, you can choose which partition to boot manually as long as you hold down alt as your mac starts up until you see the prompt. This works fine with the wireless keyboard too thankfully.

Also, this 'fix' really does need to be added to the support pdf files.

I think I'm going to cry from joy. I bought a new iMac and tried to partition it. Needless to say, 30 minutes of Apple Support and 4 tries later I had given up. This solution worked. IT WORKED.

I removed the external harddrive, and as an extra measure, I moved the USB for the optical drive from the second port of four all the way to the left port. I'm currently as happy as a clam.