how do i set the thumb button on my mouse for autocad?

Answer 1

If your mouse allows it, it will be in the mouse-settings panel.
Go to Control Panel > Mouse > Device Settings
Make sure the mouse you want to edit is highlighted
Click Settings
In the left-hand panel click the box next to Buttons
click the name of the button that you want to edit the action for
In the list on the right find the action "Run a program of your choosing"
Click "configure"
In the window that opens, click "Browse" and navigate to the folder of the program that you want to have run when you click it.
Double click on the program (should be something like autocad.exe)
Click Apply then OK

that should do it.