As a rule, a user’s mouse hand is determined by the hand with which they write. Right-handed users position the mouse to the right of the keyboard while left-handed users might choose to position the mouse to the left of the keyboard. Some left-handed users choose to acclimate themselves to the mouse on the right side (especially if they share their computer with a right-handed user); others that are right-handed choose to switch to using their left hand to alleviate repetitive stress injuries in their right hand or wrist.
If you decide to switch your mouse to the left, you may want to consider altering the mouse button assignments – some people just find it more natural to have the “left” click action, or primary mouse button, always controlled by the index finger, and the “right” click action, or secondary mouse button, controlled by the middle finger.
If you do want to reverse the function of the mouse buttons, the switch is quite easy in Windows 8.1. You need to start in the Control Panel, which can be opened directly just by holding down the Windows key while pressing I, and then clicking the Control Panel from the choices that come up on the right.
From the control panel, click Hardware and Sound, and under Devices and Printers, click Mouse.
This will open the Mouse Properties window. From here you’ll change the primary mouse button to right by selecting “Switch primary and secondary buttons.”
While you’re in the Mouse Properties window, you can customize their other mouse settings, including Double-Click speed and Pointer options.