Unable to install system images for the Android SDK: "Failed to create directory" I've just installed Xamarin, to use C# on Android: on their tutorial about how to install the emulator here. I saw they installed Intel x86 Atom system image and ARM v7a system image, so I did the same and got this with both API 18 and 15, but only ARM vt7a (15) was successfully installed

Downloading ARM EABI v7a System Image, Android API 18, revision 2
Installing ARM ABIv7a System Image, Android API 18, revision 2
Failed to create directory C:/Program Files (x86)/Android/android-sdk-windows/system-images/android-18/armeabi-v7a
Downloading Intel x86 Atom System Image, Android API 18, revision 1
Installing Intel x86 Atom System Image, Android API 18, revision 1
Failed to create directory C:/Program Files (x86)/Android/android-sdk-windows/system-images/android-18/x86Done.
Nothing was installed.

I'm on win 8, 64-bit, do you think the problem is my laptop architecture?
The SDK needs to be run as admistrator to be able to write those files.

Just retry and run it with elevated rights.