Most users don't need to download anything. Windows 10 comes pre-installed with the app (formerly "Alarms & Clock"), which includes a dedicated stopwatch. Microsoft Support How to use the stopwatch in the Clock app in Windows
Whether you are timing a workout, tracking work hours, or running a lab experiment, finding a reliable stopwatch for your PC is simple. Windows 10 includes a powerful built-in tool that requires no extra installation, though several high-rated third-party apps offer specialized features like "always-on-top" modes and Excel exports. stopwatch download windows 10