The Group Policy setting "Block unsigned theme installation" for System Center Mobile Device Manager 2008 is not correctly applied to Windows Mobile 6.1 mobile devices

To work around the behavior when set to Enable, you must sign the default theme files you want to enable users to install. To work around the behavior when set to Disable, follow the procedures below:


Important The following workaround applies only to the English version of Microsoft System Center Mobile Device Manger 2008. There are no workarounds for other language versions of the product at this time.


Warning Serious problems might occur if you modify system files incorrectly. These problems might require that you reinstall server software or components of server software. Microsoft cannot guarantee that these problems can be solved. Modify the system files at your own risk.
Important: The following workaround requires you to modify an important system file. Make sure that you back up the referenced file before you modify it. Make sure that you know how to restore the system file if a problem occurs. Do not proceed with the following procedure if you do not know how to back up and restore a file. Revert to the original file if you encounter any problems with the workaround.


The following steps modify the ADM template file that includes the Block unsigned theme installation Group Policy setting. When you have successfully modified the file, you can use the Block unsigned theme installation Group Policy setting to correctly update managed devices.

1. On the computer on which you have installed the MDM Administrator Tools, navigate to the %windir%\INF folder.
2. Type the following at a command prompt to make a backup copy of the mobile.adm file:
   copy mobile.adm mobile.adm.bak
3. In a text editor, such as Notepad, edit the mobile.adm file to change the VALUEOFF setting for Policy_BlockUnsignedThemes
   
   Replace this:
   
   POLICY !!Policy_BlockUnsignedThemes
   EXPLAIN !!Explain_BlockUnsignedThemes
   VALUENAME "4103"
   VALUEON NUMERIC 0
   VALUEOFF NUMERIC 16
   END POLICY
   
   with this:
   
   POLICY !!Policy_BlockUnsignedThemes
   EXPLAIN !!Explain_BlockUnsignedThemes
   VALUENAME "4103"
   VALUEON NUMERIC 0
   VALUEOFF NUMERIC 64
   END POLICY
4. Save the file and exit the text editor.

To apply the new setting to managed devices, you must update the Block unsigned theme installation Group Policy setting in MDM. To refresh the setting in MDM, in the MDM Console run the following cmdlet:


Update-MobilePolicyCalculation <device>

Where <device> is the managed device on which you want to update the Group Policy setting. New settings are pushed down to managed devices during the next synchronization with MDM.