On a MacBook Pro, you hold down the ctrl key and click. I haven't figuure out how to do it when you're in Windows on a MacBook Pro. I did figure out ctrl-alt-delete, however...
Select "System Preferences..." from the Apple menu (top-left corner of your screen), click "Keyboard & Mouse", click the "Trackpad" tab and turn on the option that says "Place two fingers on trackpad and click button for secondary click". You should find that two-finger right-clicking is easier than ctrl-clicking and works in both Mac OS X and Windows.
With a MacBook Pro Core 2 Duo, Control+Click (as well as placing two fingers on the trackpad and clicking, as suggested by brkirch) works fine for me. David
I just plug in USB MS Basic Optical Mouse don't install the MS mouse software just let parallels tools deal with the mouse two buttons wheel and wheel click holding the wheel down in Mac OS is useful too works like Apple + tab 5 button mouse is overkill Hugh W
