About a month ago, we installed a small Windows Server 2012 R2 Essentials network (one server, eight workstations). Everything was fine and the speed was excellent (gigabit Ethernet). Yesterday around noon, the communication speed between the workstations and server dropped dramatically. Now even simple things like changing directories on the server (from a workstation) and opening and closing MS Office files (Word, Excel) housed on the server takes a very long time. The primary line-of-business application is on the server (client/server configuration) and takes several minutes just to open.
The server itself works fine. It loads the primary business application immediately, as it always has. Both the server and the workstations (Windows 7 Professional OS) can access the Internet, email etc. fine. The problem seems to be very sluggish workstation access to the server. This process worked flawlessly for over thirty days, then all of the sudden became mired in quicksand.
There is no sign of a hardware problem (although I am going to bring in a new Ethernet switch and piece of CAT-5e cable for testing purposes). Assuming that this is not due to a hardware failure, could it be a local DNS problem stemming from the server? If so, what can we do to fix it? Would it be easier/more efficient to restore the entire server image from a recent backup? As I say, everything worked fine until yesterday afternoon. Nothing was added or changed at that time, as far as I can determine.
One more thing. The workstations do properly set up the mapped drives to the server when they are initially turned on. I also noticed that the workstations were slightly quicker on the server the first time they accessed it (e.g., changing server directories).
Thanks very much for any assistance anyone can