File Sharing

I have two Dell Notebooks (Latitude E7440) and a XPS 13  9310(Just got it a week ago.

When I try to file share my E7740 will talk to my Precision Computer (File server) When I try to share a file on either the Latitude or the XPS i can see the computers that I am trying to communicate to but I get the following error:Windows Cannot Access \\Desktop-EXXXXXXXI

You do not have permission to access \\Desktop-EXXXXXXXI Contact your network administrator to request access.

Strangely it happens in both directions I have toggled the TURN ON/OFF protected sharing but still no File sharing...Anybody ??