I came across an interesting (if very frustrating) issue recently when a client provided me with an updated version of Windows Server 2012 R2. Prior to being handed the new media, I was using my own copy of Server 2012 R2 which is Build 6.3.9600.16384. I set up my MDT build which had a task sequence for each version of Server 2012 R2, Standard, Standard Core, Datacenter and Datacenter Core.  Everything was fine and the UI language was configured correctly throughout.

I received the new media which was Build 6.3.9600.17415 and replaced my original copy of Server with this new version. All appeared to be fine until I tried to log in to the two Server Core versions where my password wasn’t being accepted. It transpires that these have some kind of bug / difference whereby the Input Locale doesn’t change to the configured language. In my case, I had an American (en-us) keyboard and I wanted to use an English (en-gb) keyboard. Weirdly, this was only the case for the core versions; the GUI versions were fine.

I spent a good deal of time scouring the internet for a fix to this and it appears quite a few people had the same issue, eg:
https://social.technet.microsoft.com/Forums/windowsserver/en-US/d82dd905-e346-4a94-87e6-a78d59f4941c/keyboard-layout-wrong-on-logon-screen-but-fine-on-desktop?forum=windowsserver2008r2general
or
http://windowsitpro.com/systems-management/how-do-i-configure-default-keyboard-layout-during-login

This one was also interesting but the application of the fix wasn’t explained clearly and I gave up on it.

Mostly, the ‘fix’ was to change the HKEY_CURRENT_USER\Keyboard Layout\Preload setting to the proper value and this does seem to work if you log on and change this manually in the registry. However I could not get this setting to stick when I applied it through any scripting mechanism.

I eventually found a solution though through group policy which I applied during the build. The steps below are for MDT but the same can easily be applied for SCCM.

1. 1. Create a new GPO and browse to Computer Configuration\Policies\Admin Templates\System\Locale Services
   2. Change Disallow copying of user input methods to the system account for sign in to Enabled.
   3. Create a backup of the policy and copy it to your deployment share. Rename it from {GUID} to LogonKB. I created a custom directory to store this in called Custom2012R2. Under this I had a directory called GPOBackup which contain any GPOs I need to apply.
   4. Download a copy of lgpo.exe and stick it in your tools\%architecture% directory (in practice you want the x64 version)
   5. Create a TS step just before the Tattoo step called Copy GPOs Locally as below

Command line: xcopy "%DEPLOYROOT%\Custom_2012R2\GPOBackup" C:\Windows\Temp /e /i

6. Next, create another step to apply the GPO, directly after the copy step and call this Apply GPO logon keyboard.
Command line:

"%DEPLOYROOT%\Tools\%ARCHITECTURE%\lgpo.exe" /g "C:\Windows\Temp\LogonKB"

It is important these two steps are early in the task sequence as the ‘damage’ is already done if you apply them too late. What is actually happening is that the GPO you have applied is preventing the Input Locale from being copied over to the login screen keyboard locale. You can see this before and after by running up the systeminfo command from a command prompt. On a machine without the application of the GPO the Input Locale will show up as:

 Input Locale:   en-us;English (united States)

and this will get copied over to the login screen language during build time. The GPO prevents this from happening and keeps the setting at en-gb.

I hope this will save others many hours of frustration!