Install a full version of Windows instead of using an upgrade version. Upgrade versions can't be installed because the built-in 64GB flash drive can only allocate 34GB of space for a Windows partition. This is not enough free space to accommodate an upgrade installation.
These steps erase the current Windows partition on your Mac. Make sure you have a backup of any important data on your Windows partition before performing these steps.
Use these steps to remove your current installation of Windows and then reinstall a full version of Windows:
- Back up your data from the Windows partition.
- Start your Mac from OS X.
- From the Finder, choose Go > Utilities.
- Open Boot Camp Assistant from the Utilities window.
- Click Continue, then select the option to "Remove Windows… or later version".
- After Boot Camp finishes removing your Windows partition, use Boot Camp Assistant to install a full version of Windows.
- Once installation completes, restore your data from your backup.