Windows 8.1 running on USB drive or SD Card?

You can't install Windows on "removable" media, like USB, SD cards, external drives, etc.

You can install Windows FROM these devices (I.e. instead of DVD), but you cannot install Windows TO these devices.

The ONLY exception is a feature of Windows 8/8.1 ENTERPRISE (ONLY) called Windows To Go; Enterprise can only be obtained through a volume license account with Microsoft and is not available to Windows 8/8.1 or 8/8.1 Pro users.

Do you know "windows to go"? If you have Windows 8/8.1 Enterprise Edition, you can with its built-in windows to go create a portable Windows.If you have no Enterprise Edition, you can try aomei partition assistant with its new feature"windows to go create"USB drive is OK, SD card is not. I hope this could help you.

Tutorial:http://www.microsoft.com/en-us/windows/enterprise/products-and-technologies/devices/windowstogo.aspx

http://www.disk-partition.com/features/windows-to-go-creator.html

"Do you know "windows to go"? If you have Windows 8/8.1 Enterprise Edition, you can with its built-in windows to go create a portable Windows."

That's what I said :)

"If you have no Enterprise Edition, you can try aomei partition assistant with its new feature"windows to go create"USB drive is OK"

You must use Enterprise; it is a violation of the licensing for any other version to install it on a removable drive.

Wrong!

'WIM Installer' will install any version of Windows to a SD or external USB drive. I've been using it for almost 2 years

Wrong!

What's 'wrong'? That you can't install to removable media? or that it violates the EULA? All it takes is 1) changing the removable media to present as non-removable, or 2) changing the software to ignore the removable flag (explicitly violates EULA). I didn't say it was impossible. I said anything other than Windows To Go violates the licensing agreement you agree to when you run Windows.