A while back, I installed Windows 8 on my MacBook Air (mid 2013 model) using Bootcamp. It never really worked, (it would freeze all the time, the WiFi would cut in and out, etc.) so I got rid of it. I tried to do this through Bootcamp again, but for whatever reason this didn't work, so I booted up on a live Ubuntu USB and manually erased the NTFS partition for Windows.