Hello Milton,
Thank you for posting your query on Microsoft Community forum.
I totally agree with you Milton that language packs for Windows 8 and Windows 8.1 different. After you upgrade to Windows 8.1, language packs that were installed before the upgrade are no longer available. You can still switch to the keyboard layout of the
languages that were installed before the upgrade. However, the only available display language is the base language version of the Windows installation.
This issue occurs because Windows 8 and Windows 8.1 have version-specific language packs. When you upgrade Windows 8 to Windows 8.1, the operating system reverts to its base language version. After the upgrade is finished, you have to reinstall any language
packs that you require.
As per your description you have already tried the troubleshooting steps provided in the
KB2910256 knowledge base. So I would request you to follow the suggestion provided by
Cyber_Defend_Team replied on August 6, 2014 in the following thread and see if it works for you.
Windows 8.1 Pro Language Problem
Hope the information provided is helpful. If you have more concerns related to Windows do get back to us and we will be happy to assist you.
Regards.