Both Windows 98 Second Edition and Windows 2000 Professional will detect the IntelliMouse Optical properly even without installing the IntelliPoint. But to take advantage of its functions, you need to install IntelliPoint.

I tested the USB connection only but I assume PS/2 will work just as well. I chose USB because it refreshes 120 times a second, instead of the PS/2's 100Hz. (Note: After installing IntelliPoint, the refresh rate of the PS/2 connection automatically bumps up to 100Hz, instead of default 40Hz in Windows 9x or 60Hz in NT)

Features

The box includes the mouse with a plastic cover, a small multi-language manual, the IntelliPoint 3.1 CD and a PS/2 converter attached to the USB connector.

As I mentioned earlier, this mouse does not use the traditional mouse ball. Instead, it uses an optical sensor and has all the features found on the IntelliMouse Explorer, its bigger brother. Because of its ball-less design, it will work on uneven surfaces like your body and even work upside down, which is not the case for mechanical mice.

It has five buttons including the one on the mouse wheel. The default settings are Click, Right Click, and Autoscroll which is common for mice with a wheel. But the additional buttons are for Internet browser navigation - Left Side button for Back, Right Side button for Forward, the most common internet browsing functions. Using the bundled IntelliPoint 3.1 software (IntelliPoint 3.2 is available for download from Microsoft's website), you can always change to other shortcut keys like double click for Explore My Computer, Copy or Paste. But I prefer to leave it default because I surf a lot. :D

It is also compatible with Macs using the USB port. I personally never own or use a Mac so I can't test it in the Mac OS environment.