Windows 8 RT nunca va a funcionar en Raspberry Pi.
Raspberry Pi usa ARM v6, y Windows 8 RT usa ARM v7.
(Lo siento; no hablo el español bien)
{sig} Setup: Original versionRaspberry Pi (B, rev1, 256MB), Dell 2001FP monitor (1600x1200), 8GB Class 4 SD Card with Raspbian and XBMC, DD-WRT wireless bridge