Full Windows Install using Bootcamp I have a MacBook Air to which I have to install Windows 8.1 completely. I wiped the machine clean and did a common Windows install, but Windows didn't run well and while I was able to install some of the drivers that came along with bootcamp I downloaded from Apple, I could not just execute the package as a whole, as it was "not meant for my computer". So I decided to recover OS X (El Capitan), have it installed to an external drive and then use Bootcamp to do a full install of Windows to the main drive. But now he doesn't allow me to use the full drive, he always wants to keep a share of about 10 GB for an "OS X" that does not exist.

Is there a way to tell Bootcamp to use the whole disk? Otherwise, when I download macOS Sierra and create an install medium from it, will I be able to fetch the Bootcamp installer from this medium?
No. Install OSX, then use Bootcamp Assistant to make and format a new partition and install Windows. Only use BootcampAssistant, do not use DiskUtility or any other tool.
When there is something wrong with the Windows installation later on, you can restart in OSX and correct it with BootcampAssistant.
Let about 15GB minimum free in the OSX partition.