Be cautious of "highly compressed" links on unknown blogs that ask you to disable your antivirus or complete surveys. Always stick to reputable community sites or forums dedicated to and emulation . Are you planning to play this on a PC or a mobile device ?
Open your emulator and point the "Game Directory" to the folder containing your ISO.
A genuine compressed game should come in formats like .ISO, .7z, or .RAR. If a "highly compressed link" asks you to run an .exe installer to unpack it, proceed with extreme caution.