I upgraded my OS to Windows 8.1. Since, I am having login and CPU load issues since upgrading from Windows 7 Pro. Same hardware just a different OS. I can understand the login issue could be caused by my multiple installs trying to get the software to work. I don't understand the 99% CPU load. The load starts as soon as the Milestone services start. Before I can even open up the management tools. I am back to using Blue Iris which runs the CPU at 32%. System Spec: [h=1]Lenovo ThinkServer TS140 70A4001LUX[/h]Xeon E3-1225 v3 8GB ECC Memory Windows 8.1 Pro All drivers are up to date Cameras: 2 each: Hikvision DS-2CD2032-I 2 each: Dahua IPC-HFW4300S I am open to suggestions... I am thinking that I will not be using the software while I have Windows 8.1 installed. Good note, I am spending a lot more time learning Blue Iris.