Hola ... mira este link con información muy interesante sobre lo que te sucede, para las unidades de red al final del artículo te dicen como desactivar la vista protegida
http://www.askvg.com/how-to-disable-protected-view-in-microsoft-office-while-opening-email-attachments-or-downloaded-files/
NOTE For Network Drives:
You need to enable the checkbox "Allow Trusted Locations on my network (not recommended)". It's present under the list of locations that you added. Once you enable the option, it'll allow you to open documents from a network share.
You can then enter either the drive letter or the UNC and it should work without any problem.
El problema es que tienes que hacerlo en cada equipo ... :-(
Si te planteas hacerlo mediante GPO míra estos links
https://social.technet.microsoft.com/Forums/office/en-US/26c39706-3dec-42e0-a39b-0faea295367d/how-to-turn-off-protected-view-in-office-2010-using-gpo?forum=officeitproprevious
https://msdn.microsoft.com/en-us/library/ff400327(v=office.14).aspx
Y este relacionado con problemas
https://support.microsoft.com/kb/983047?wa=wsignin1.0
Daniel Graciá - Madrid / España
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