We are anticipating having to upgrade from 16.1 to 18.1 as 16.1 will no longer be supported with year end updates.  We are a small company and have a workstation that serves as a peer to peer network to which 3 other workstations are connected.  The server workstation is not an actual server and is running Windows 7 Pro as are our other workstations. I read the release notes which said that on the server one has to be running Windows server 2008 or 2012 or 2016. I called Timberline and the rep said that yes the server has to be running a Server Operating system.  I am questioning this as in the past, I have had the same discussion and when Timberline support understood that ours was a peer to peer and not an actual server we were then told that Windows 7 pro would work fine in that instance.  I am not completey sure that support understood what I was asking. So (at last) my question. Can I upgrade to 18.1 using Windows 7 pro on a peer to peer server or do I indeed have to install a new operating system in order for the program to work?