You can solve this issue without adjusting your mouse movement by letting a program automatically stop your cursor when it hits the edge of a display (even if your second monitor is connected.) ...

This article explains how to use Dual Monitor Tools to lock the mouse cursor to a single screen on a multi-monitor setup. How Do I Stop My Mouse Moving to My Second Monitor? While some games and ...

Another way to stop your mouse from moving to your second monitor is to adjust your display settings. Right-click the desktop to find the display settings link.