What kind of mouse? Have you installed drivers specific to that mouse?
Max expects (actually, it requires) a standard 3-button mouse. Custom drivers can affect the operation of the mouse so try removing any specific drivers and allow the mouse to use the ones built into Windows.
Max 2016 (SP1/EXT1)
Win7Pro x64 (SP1). i5-3570K @ 4.4GHz, 8Gb Ram, DX11.
nVidia GTX760 (2GB) (Driver 430.86).