You don’t technically install an ISO file itself. An ISO file is a digital copy of an optical disc (like a CD, DVD, or Blu-ray). You either extract its contents, mount it as a virtual drive, or write/burn it to a USB drive to install the operating system or software contained inside.
Never download ISO files from untrusted torrent or warez sites. They often contain malware. Always get ISOs directly from the official publisher (Microsoft, Canonical, Adobe, etc.). how to install iso file