This update is not applicable for Windows 8.1 Preview
If you have an Surface and the default language is not en-US you can’t upgrade to windows RT 8.1 preview. Well here is the Fix. This all is on your own risk.
The update is in two steps. first we need to download the KB2849636 and during the install you got.
This update is not applicable
Download the update file from the Windows 8.1 preview site
Now Extract the MSU file in a folder
Open a Command prompt in administrator mode.
Expand –F:* c:\preview\Windows8-RT-KB2849636*.msu C:\preview\
the Windows8-RT-KB2849636*.msu can be different depends on the Surface system
DISM.exe /Online /Add-Package /PackagePath:c:\preview\Windows8-RT-KB2849636-arm.cab
Beware of the update naming and adjust it as needed to your system.
If you do not name /rename the file you got an error 0x80070003 as in your screen shot.
If it goes well there will be a reboot in the end and the Windows 8.1 preview update will be in the store but still not working.
therefor you need the next step
Create a restore drive using a USB stick before you start If you want one.
Install en-us as a language, click options and download pack, make your primary language but do not restart.
Open Regedit and navigate to HKey_Local_Machine\System\CurrentControlSet\Control\Nls\Language
Scroll to the bottom change the value of installlanguage from 0809 (EN-GB) to 0409 (EN-US)
Now go to the http://preview.windows.com or go to the store and download the Preview version
You should be prompted that 8.1 preview is available in the store or you can go to the store yourself to find the install.
Once the Preview is installed you can go back to the en-GB language.