magic mouse system preferences - one-click

I have a brand new iMac running the latest Yosemite. It came with a wireless keyboard and magic mouse, both of which are paired with the computer just fine via Bluetooth. However, when I open system preferences for the mouse, the options are only available for what looks like an old one-click mouse (see below).

If I click on "Set up bluetooth mouse" it just continues to search and finds nothing. I have restarted the computer, taken the batteries out of the mouse, un-paired and re-paired it several times. Nothing is working.

I've looked for other USB programs already and there are none (nor should there be since it's a new computer).

I took the mouse home and successfully paired it with my Air and saw the normal Magic Mouse screen with all of the videos and scroll preferences.

Can anyone help? Thanks in advance.