Windows provides a control to cut off noises from your computer.

Mice still click, and most people like that.

Having designed controls many times, I just want to say that controls that don't provide immediate feedback are problematic for many users.

The click of a mouse is comparitively quiet. Think of the membrane switches on your microwave--they're so quiet that the designers usually add a 'beep' to tell you that a button has been pressed.

In a loud environement, sometimes the feedback is visual--an LED or something.

With the mouse, it's more important for you to hear (or feel) the click because sometimes the computer doesn't respond immediately and you'll be tempted to push it again (thinking "maybe it didn't make contact the first time?"). Bad thing can happen. If you push 'approve payment' two times on your credit card, you pay them twice.

It's also a balancing act for switch life. the snap-dome switch that most mice use is good for a million cycles. membranes and conductive elastomer switches don't normally work half that many. But if you try a few brands of mouse, I'm sure you'll find louder and quieter ones.