How do I change the proportional edit radius?

Mouse wheel only zooms in and out, and page in and out doesn’t seem to do anything. I’m using a latptop and w7.

Any ideas?

To see and change the radius you need the following:
Make sure you’re in Edit mode*
Turn on proportional editing (O key)
Select a vertex or vertices
Hit G S or R. the P.E. radius should appear.
MMB or page up/down to change radius.

*Proportional editing works in Object mode too, with multiple objects Shift-selected.

And of course the selected vertex or vertices must be visible in the 3DView port.