I dont think that Microsoft distribute windows mobile to anyone except OEMs (read that somewhere whilst googling) - and then you need the xperia panels too for the language you want. When I spoke to SE about converting my swedish X1 to an english language OS with the Swedish keyboard - they gave me multiple different answers - but the impression I got was that it is technically possible - but will require you to reflash the OS - and you'll need the xperia panels too - and the main stumbling block is that Microsoft will not be likely to allow free download of their OS - but maybe at an SE service centre they can do it for you... I did get a hint that SE were investigating this - and may update the support site...