UPDATE: Microsoft have fixed the issue and you can now install Windows 8.1 Preview on a Surface RT, see our post
If you are looking forward to installing the preview of Windows RT 8.1 on your Surface and you have UK version of the Surface RT then hold on for a moment. The preview released yesterday at Microsoft’s Build conference isn’t compatible with the UK version of the Surface RT. If you try and install the preview you get the following message:
“The update is not applicable to your computer.”
The reason is due to the preview not supported on English (UK) language installations. The Surface RT devices sold in the UK all have English UK language packs installed so you can’t install the preview. There are 13 supported languages in preview but not UK English. If you have Windows 8 you can install Windows 8.1 Preview from an image but you can’t do that with Windows RT.
There is a very long thread about it on Microsoft’s Answers forum with lots of unhappy UK Surface owners itching to get the preview and they are a few people offering tips and workarounds but there is a warning from a Microsoft support engineer.
Windows RT users
Please do not change your base language just to install the Preview. If you do this and then update to the preview version, you will permanently change your base language on these devices. This happens because we create a new restore image based on your selected 8.1 base language during install.
Also, as we noted on the download page, if you’ve installed a language pack on Windows RT, we ask you not to install Windows RT 8.1 Preview at this time. A fix will be available soon for updating through the store with a language pack installed, so please check back.
It looks like it’s more of an oversight than a deliberate policy by Microsoft as Charles from Microsoft says :
Windows RT devices with at least one Language Pack installed are asked to wait as we address a setup issue. That is the fix coming soon I mention.
So UK Surface RT owners will just have to sit tight for now and wait.