So... I was success unpacking language files from my Lumia 520, here's guide how to install it

. But keep in mind that I've not tested it because I haven't got a W1, it should work, and also if fail, you can't brick your phone.
The Ascend W1 should be connected to computer in mass storage mode. Copy the folder in the zip file at
Windows\System32. Then apply the following registry entries:
Code:
[HKEY_LOCAL_MACHINE\Microsoft\Speech\UXLanguages]
"nl-NL\@"=sz:Netherlands
"nl-NL\Culture"=sz:Netherlands
"nl-NL\Language"=hex:413
"nl-NL\Recognizer"=sz:HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\SPEECH\Recognizers\Tokens\MS-1033-110-WINMO
"nl-NL\Voice"=sz:HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\SPEECH\Voices\Tokens\MSTTS_V110_enUS_ZiraM
"nl-NL\VoiceGender"=hex:1
@nilezon: For Swedish you need to use sv-SE instead of nl-NL and:
, not
, not
Now language should appear, if you apply it, all should be in this lang, except the voice, I will work on that
IMPORTANT: Don't write "sz:" and "hex:"!! They are only there for know what kind of key to make!!!
All keys must be created! They are not there, you must create it!
Have fun