How to test your mouse
- Move your pointer over the dark panel.
- Click each button: left, right, the wheel (middle click) and, if your mouse has them, the back and forward side buttons. Each one lights up and counts its presses.
- Scroll the wheel up and down and watch the scroll counters.
- Move the mouse around quickly in circles to estimate its polling rate.
Inside the panel, right-clicks and side buttons are captured, so no menus pop up and the page doesn't go back or forward.
Finding a double-click fault
A very common problem with older mice is a worn switch that sends two clicks when you press once. It causes files to open when you only meant to select them, or drag-and-drop to let go mid-drag. Click the left button slowly, one click at a time, about twenty times. If the test reports clicks closer together than the alarm setting (80 ms by default, far faster than anyone can click on purpose), the switch is "chattering" and is the likely culprit.
What to do about it: blowing compressed air into the gap around the button sometimes helps for a while. Check whether the mouse is still under warranty, or, if you're handy with a small screwdriver, replacement switches are cheap. Windows also lets you slow the double-click speed in mouse settings, which can hide mild cases.
Polling rate
Polling rate is how often the mouse reports its position to the computer. Office mice usually report 125 times a second (125 Hz); gaming mice report 500, 1000 Hz or more, which can feel smoother. Move the mouse quickly and the reading shows roughly what your browser receives. Browsers group movement events together, so treat it as an estimate: a reading near 125 means a standard mouse, while several hundred or more suggests a high polling rate is active. Some gaming mice need their own software to switch to a higher rate.
Scroll wheel problems
If the counter jumps up when you scroll down, or misses steps, the wheel's sensor is probably dirty or worn. Spin the wheel firmly in both directions a few times and blow out any dust; this often fixes jumpy scrolling.