Solved! (I think...)
I spent hours yesterday trying to find the solution to this problem, trying stuff at random and search the internet for ideas. Nothing worked, but I was reading about one person who said his touch pad was causing his flickering problem. I don't have a touch pad, but I do have a touch monitor. In fact I have two monitors, one touch and one is not, which may or may not having anything to do with it.
Anyway, the touch screen monitor was the problem. The first way to solve this, in my situation, was to go to Device Manager > Human Interface Devices > HID-compliant touch screen, right click and disable the device. This worked immediately.
However, as I realized later, the far easier solution is to reach around to the back of the monitor and unplug the usb cord that connects the monitor's touch screen functionalities to the computer. This too caused the flickering mouse cursor to stop.
Very frustrating problem if you don't know the solution. But when you do it is easy. Hope this helps someone.