It's not as hard as it seems, I'm on Windows 10 but it should be the same on Windows 8 and even Windows 7
- on Windows 8, Press
Win
+Q
to invoke Search. - Type
Region
(or equivalent to this in your language) . - Click on
Administrative
tab. - Click
Copy Settings
(might require Admin password if your account is a standard user).
In this window you'll see the current language settings for your account and the ones for Welcome Screen as well
- Click
Welcome screen and system accounts
checkbox underCopy your current settings to:
- Click
Ok
and the welcome screen language should now be changed.