My Logitech mouse came with its own software that controls the mouse settings. Depending on what manufacturer's mouse you have the middle wheel setting might need to be set differently. Earlier Mice that I had would require the scroll wheel to be set to the "Autoscroll" setting. My current Logitech likes the setting called "Middle Button" setting with Vista 64 bit. Here is a screen shot of my current settings.
Hope this helps.
Thanks... I went into that setpoint window and didn't think to click on the zoom, I had middle button or scroll button in my mind.
Thought I'd add my 2c as well - I have a Logitech mouse and also installed the Setpoint drivers and had no issues with the mouse.
However, I then plugged in a simple Microsoft mouse and found I could not rotate the model in SolidWorks with the middle mouse button. Windows Control Panel settings did not help, and Setpoint showed the mouse as having no scroll wheel (i.e. it had a picture of a 2 button mouse). The only solution I've found is to right-click on the Setpoint icon in the system tray (bottom right of the task bar, next to the clock) and close Setpoint - then the middle mouse button works as expected!
Just thought I'd add this in case it comes up for someone else.
December 6 2015
I just bought a Logitech M705 mouse for use with Solidworks on a 64-bit windows 7 PC and the middle mouse button would not scroll; nor would the combination of middle mouse button and CTRL key cause the model to pan. After reading several forums on this, I had no luck, but after some trial and error I did come up with a solution that works every time;
1. Download and run/install latest Logitech Setpoint s/w from their website
2. Restart computer and then Start Setpoint and select the Mouse Tab. option 3 - middle mouse button
3. For the Middle button, select the Middle button task.
4. Next, select option 6. Middle Button (side scrolling left) and select "other" task and then "select function"
5. In the "Select Task" pop-up window, use the pull-down menu to select "Middle button"
6. Repeat for option 7. (side scrolling right) in the main button menu -> select "other" task, then "select function" and then use pull-down menu again to select Middle button
Works perfectly with SolidWorks after these changes for both rotating and panning (with CTRL key)
12-year user of SolidWorks - best CAD mechanical design software in the world
Just to keep this link going for future readers. Rotating my screen with the MMB wasn't working either. It's a Logitech M215. It doesn't run with Logitech settings.
My solution was much more low-tech then that. The switch inside the mouse was dirty.
I noticed that if I pushed down harder on the MMB it worked, and my view rotated. I opened the mouse up, and dabbed the push button switch in the middle with alcohol. Now it is working fine.