Windows 2012 File Services Slow Response

Hello All,

I am experiencing a rather annoying problem with Windows 2012 Fileservices, my problem is the following :
Opening Office files takes a long time on a windows 7 machines, other files are perfectly fine.

I have searched this issue and i seen that there a few registry tweaks to fine tune, i did that and it didn't help much.

My setup is :
VM Cluster / SAN / Dedicated fiber storage for Windows 2012 Fileserv that's mapped as a RAW device .

Any idea's ?

Thanks !