Greetings, I am curious to see if I can kind of get to the bottom of this to figure out where the bottleneck or problem might be. Some users complain that the background colors of some parts of program interfaces (like the background of the ribbon in Office 2013 programs) turn black, but buttons still function and you can read the text of buttons (but barely) and see icons. Sometimes portions of the screen are black. Technical thoughts is that somehow that part of the screen cache failed to update/messed up thus being black, and easily goes away if you minimize and maximize applications a few times or move an application's window over the black area. Sometimes users experience lag in their typing (as opposed to letters on the screen showing up "instantly"). In our buildings, all networking equipment got replaced with brand new Cisco equipment. In our oldest building, the only thing that hasn't been replaced is existing Ethernet runs; we did get two brand new fiber runs to go from our core Cisco router to an HP switch --> RaiseCom that takes in the fiber. Our other buildings are newer constructions so bad Ethernet runs are unlikely, plus that they were run and certified by professionals of a company that does this for a living. Our core infrastructure is located in a private "cloud" at a big and well known provider that I will not name. Our facilities have 100mbit connectivity to the internet.