A "highly compressed" version usually means the game files have been packed using tools like 7-Zip or KGB Archiver. This reduces the setup size from ~4GB down to 1GB or even 500MB.
If your monitor is 1080p or 4K, use a "Wide Screen Fix" plugin or Kitserver to force the game to modern aspect ratios. link pes 2009 highly compressed pc
Highly compressed setups often use custom scripts that antivirus software might flag as a false positive. A "highly compressed" version usually means the game