1. Install with a VM
You can setup VirtualBox to use a raw hard drive as one of its drives. If you mount that drive and a Windows 8 installation ISO, you will be able to install Windows very quickly. Usually a simple reboot should be enough to be able to use Windows.
2. Simply copy the files of an existing installation. (caveat: Apps no longer worked for me, and it was very slow)
3. If booting does not work, manually set up the boot disk
- Copy bcdboot from x:\windows\system32\bcdboot to your windows drive, e.g. C:.
- Use it to make drive X bootable: C:\bcdboot X:\windows /s b:
Of course the target drive X should be a primary partition formatted with nfts already and the partition should be active.