Many years ago, PC Magazine poked fun at an advertisement which featured the picture of a woman sitting in front of a computer holding a mouse in her right hand lifted about a foot above the desk. Clearly, neither the model nor the photographer had a clue what the mouse was for (they were a fairly new thing in the PC universe back then, though quite familiar to Mac users).
Though the ad was quite funny back then, I remembered it recently when I got a new computer running Windows XP. I had hard time using my new mouse. It seems extremely sensitive. When I click, the system often thinks that I am trying to drag. When I double click, the system often thinks that I have moved the mouse slightly between the two clicks and interprets that as two single clicks rather than a double click.
The control panel offers various options, but none to lower the sensitivity of the mouse. Inspired by the silly ad of computer yesteryear, I now lift the mouse just slightly above the surface before clicking as well as before double clicking. Because the mouse ball is not touching any surface, it remains stationary enough for the mouse not to tell the system that it detected any movement between the time I press the button and time I release it.
So, if your mouse is too sensitive, or if your hands are not as steady as they used to be when you were younger, just position your mouse cursor where you need it, lift the mouse just a bit, then click or double click, and lower the mouse back on its pad. It works.