Mouse, Video and Music Player causing DPC spikes on my new Cubase

I have a desktop system which is causing me problems with Cubase which has just been installed.
The specifications of this system are Windows 10 64 bit, Q9300 (4x 4ghz), PNY 9400GT video card (update), 3x MOTU 896 (update). When I load a video file for rating, large ASIO peaks are obtained in any useful buffer and even with very large buffers it is rather unstable. Even without loaded video, I noticed that moving the mouse over the screen with the scissor tool selected creates similar DPC/ASIO peaks and counters. I have disabled any type of 3D mode, bells and whistles in the nvidia panel so that it works in a state optimized for performance.

What is frustrating is that I can play the video of the EXACT session on my old Dell 2 x 2.2 GHz laptop with the asio garbage driver, with Wifi enabled, while I browse and write this post with the ASIO counter at only 10% and constant with Cubase 4.5. 2!

Either way, this 100 GB video file is played by an USB3external music player.

I become mentally, so if someone has ideas or tests to offer, they are totally without ideas. Thank you in advance!