If you download Google Chrome from other places than the official website, you might download the wrong version, with bundled extras which you might not want. For example, you may have Windows 10 on 64-bit and install Chrome on 32-bit. Also, you may use an older version of Windows like Windows XP or Windows Vista, and you want a Chrome version that still works on that operating system. If you want to download a specific version of Chrome, read this tutorial: