But you can also right-click on the highlighted word and Cut and Copy will appear there as menu choices. This is faster than dragging your mouse cursor across the screen. Windows doesn't have a natural use for a third button, though the software that comes with these mice lets you program the middle button to do many things. On my system, for example, I have the middle button programmed to act as a double-click. When I want to launch something that doesn't respond naturally to the single-click feature of Windows 98, I use that middle button.
Many mice now come with a wheel that doubles as a middle button.
The wheel is used to scroll up and down through long documents, and it's great for reading Web pages. I use one of those four-button mice you talked about, a Logitech MouseMan Wheel. There's now a beta-test version of Internet Explorer 5 I can get from Microsoft. I really like version 4, and I want to try 5, but I have Windows 98. It shouldn't give you any more problems than any other beta-test software.