Occasionally a browser may insist on caching a download file from a website, e.g. the installer for a program. If you are prepared to wait, eventually the cache will expire and the latest version of a file will be downloaded. However, a quick way of clearing the cache is by opening the browser and pressing the key sequence:
i.e. hold and press the Ctrl, Shift and Delete keys together. Your browser will then pop up aasking you which data to clear from the cache. Remember to check the option to clear Images and Files from the cache and from that point you should be downloading the latest file from a website.