Setup was unable to create a new systempartition or locate an existing system partition

Hi MaxZhong,

That's a pretty specific error message. Thanks for including it.

Do you have any Thunderbolt drives connected to your computer?

Set up a Windows partition on your Mac - Apple Support

If the installer says that it couldn't create a new partition or locate an existing one, disconnect any Thunderbolt storage devices connected to your Mac. Reconnect them after installing Windows.

Best,

Nubz

I was having the same problem. Then I ensured there were no other USB drives of any kind attached to the iMac and also switched to an 8GB USB drive. That worked.

So, prior to figuring out the “solution” I was not having much luck regarding the setup of BootCamp.

I followed along with the process and get to the windows 7 installation. At the point where it asks me to Format the partition to NTFS, it appears to complete. The name of the partition loses the “Bootcamp” name (now “Disk 1 Partition 4”).

When I click “Next” I get the message “Setup was unable to create a new system partition or locate an existing system partition”, effectively ending the installation.

It was at this point that I did some research on Google. Lots and lots of issues with Windows 7 Bootcamp installs. A lot of them stalled at the same point, having to format the partition and it not going any further. Amazing that switching to a smaller drive worked.