Keeping Your Mouse Clean
Many of today's PC mice use optical sensors, which are much less susceptible to getting dirty than the old rolling-rubber-ball mice. If you have an optical mouse (usually recognizable by the illuminated LED sensor on its belly), follow the manufacturer's directions for cleaning it. The sensor usually needs only a quick wipe with a lint-free cloth.
If your mouse uses a rolling ball, it's likely to pick up more dirt and dust the longer you use it. You'll know it needs cleaning when on-screen mouse cursor movement gets jerky, slow, and/or imprecise. (Note that some stationary mice use roller balls on the top. If you have one of those, follow the manufacturer's directions for cleaning it.)
1. Disassemble the mouse.
Turn off your PC, unplug the mouse, and turn it over. You should see a locking ring around the rolling ball, usually with an arrow indicating the direction to turn to unlock it. Press the ring down, and turn it in the direction of the arrow. Remove the ring and the roller ball.
2. Clean the roller ball.
Gently rotate the roller ball in a lint-free cloth moistened with warm water or a dilute solution of dishwashing detergent. When it's clean, set it aside to dry.
3. Clean the mouse rollers.
Inside the mouse case, you'll see a pair of rollers, usually black with dirt and/or with a "string" made of lint wrapped tight around the center of each roller. Use cotton swabs moistened with 90 percent isopropyl alcohol to gently clean the rollers, making sure to rotate them and clean all surfaces. You may need to use a fingernail or pin to break the lint ring and remove it. Make sure each element is completely dry before you proceed to the next step.
4. Reassemble the mouse.
Place the roller ball back inside the mouse, and replace the locking ring, pushing it down and twisting it to ensure that it's securely locked. Check to see that the roller ball rotates freely. Plug the mouse in, turn your PC on, and confirm the mouse is working correctly.