Add the RegistryKey : MigrateNormalOnFirstBoot = 1
Customization to the Normal template is lost after you upgrade to Word 2013
This issue occurs because Word creates a new Normal.dotm file when you upgrade to Word 2013. This is so that the default document template is optimized for Word 2013.
Resolution
To resolve this issue, add the MigrateNormalOnFirstBoot registry entry to the registry before you start Word 2013 after you upgrade Word. This registry entry prevents Word 2013 from renaming existing or custom Normal.dotm files. To add the registry entry, follow these steps:
Click Start, click Run, type regedit in the Open box, and then click OK.
Locate and then click the following registry subkey:
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Word\Options
On the Edit menu, point to New, and then click DWORD (32-bit) Value.
Type MigrateNormalOnFirstBoot, and then press ENTER.
In the Details pane, right-click MigrateNormalOnFirstBoot, and then click Modify.
In the Value data box, type 1, and then click OK.
Exit Registry Editor.
The behavior of Word 2013 changes, depending on the presence and configuration of MigrateNormalOnFirstBoot. The following sections describe the behavior in more detail.
From: Customization to the Normal template is lost after you upgrade to Word 2013
In your case that will happen if the key is set at 1:
The following behavior will occurs in your case when MigrateNormalOnFirstBoot is set to 1:
Word 2013 uses the existing Normal.dotm file that is compatible with
Word 2007 and Word 2010.