By default, the left button in your mouse is the primary button and the right button is the secondary button in Windows 10.
If you wish, you can change the primary mouse button (which also changes the secondary). Remember that the change will also affect the touchpad.
Here are the steps:
Select the “Switch primary and secondary buttons” option in the “Button configuration” section.
It is important to note that the change is immediate. The primary button is now the right button, and the secondary is the left button.
Hit the “OK” button at the bottom.
Note: To return to the default setting, click “OK” at the bottom after deselecting the option above.
Click Devices > Mouse.
You can now see the “Select your primary button” drop-down list. You can find this above Mouse pointer speed.
Open it and select “Right.”
Note: To revert, select “Left” from the drop-down list above.
Go to HKEY_CURRENT_USER > Control Panel > Mouse.
Double-click SwapMouseButtons in the right pane.
Enter 0 (for default) or 1 (to switch) in the Value data field.
Click the OK button.
Sign out and then sign back in.