When you open a Microsoft Word document linked to an Excel workbook, it may take longer than expected to open, especially when connected to a network. For a registry patch to reduce such delays, see:
https://support.microsoft.com/en-us/kb/970154
Note that the registry subkey referred to in the article depends on the Office version:
• Office 2007 - HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\W ord\Options
• Office 2010 - HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\W ord\Options
• Office 2013 - HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\W ord\Options
• Office 2016 - HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\W ord\Options