How do I install Bootcamp Windows 8.1 To Go on an external USB disk (MBA 2013)

You can't. Unless Microsoft has come up with a version of Windows that can be installed on an external drive. Check with microsoft.

There are 5 supported flash drives: which one do you have?

Hardware considerations

Windows To Go works both on USB 2.0 and USB 3.0 connections, and both on legacy BIOS and UEFI firmware.^[11] Not all USB drives can be used in this environment; Microsoft has set up specific testing requirements that the USB drive manufacturer must meet in order to be a supported device. Currently there are five USB Flash memory devices listed as supported by Microsoft for Windows To Go:

• Imation IronKey Workspace^[15]
• Kingston DataTraveler Workspace^[16]
• SPYRUS Portable Workplace^[17][18]
• SPYRUS Secure Portable Workplace (w/ Hardware Encryption)^[19][20]
• SuperTalent Express RC8^[21]

Ask Microsoft, it's their software, Windows in Boot Camp is still Windows.

You're welcome, good luck.

You have to do the install from another Windows system. If you have another machine running Windows 8 already that's the easiest route but it's possible to do from Windows 7 as well.

http://tweaks.com/windows/52279/how-to-create-a-windows-to-go-usb-drive/

Now that said, while this has worked for me with two different MacBook Airs as well as a 15" Retina MBP, it doesn't work on the 2013 model Airs. I get a bluescreen booting into the drive. There were a lot of initial issues with Bootcamp not working entirely when the Airs first came out and I imagine that these are related, but until Apple fixes the issue I don't know if it will work.

Awww, the arrogance of @Csound1 .. @dharmaone, please let me know if you managed to get this working ?

i tryed to install windows 8 to go on my macbook pro 2010 but failed...

can you give more detailed information on how you got it working pls.

and furthermore have you used a win8 certified usb stick or another brand?

@Luki, for windows 8 (and above), the bootcamp version has to be 5.something. I guess you are having version 4. More help here http://support.apple.com/kb/HT5639. And no, the usb brand doesnt matter.

about this issue...

there is atarticle talk about this

but in Chinese ( Taiwan~ My Country~ )

the author use some simple (?) code with cmd

I think it isn't hard to understand

but if u need more explanation (or translation)

text me

sean905172 gmail

hope this message could help u~

hey,

i have a MacBook Air 2014. From what I read you installed win8 with bootcamp then ran win8 on Mac and created WTG from there and it worked? if I do the same thing then delete the win8 bootcamp will the WTG still work on my MBAir?