Why does Word reverse the cursor?
In Word and Other applications like Notepad++, this cursor change indicates "a whole line" is the point of selection. Clicking while the cursor is in this state will select the entire line.
Why does my mouse go up when I move it down?
Your problem could be caused by a joystick, graphics tablet, or other input devices connected to your laptop or PC. Because some of these can also control the cursor, it can lead to a conflict between them as they fight for power.