Fortunately this game has better compatibility than GTA1 when it comes to running it on modern systems so the fix is very simple, although you could still see more fixes online about other stuff like FPS unlocker, etc. This solution will only allow you to have the game all Widescreen, hope you like it :D.

1. You need to download the patch you can get it from here[thirteenag.github.io]
2. Extract the compressed file you will now have some new files
3. Copy and paste those files to your game's root location if you don't know where it is you can right click the game in your library and click on browse local files
And that's it you now can play this awesome title and you have a perk, with F5 you could save your progress anywhere but be aware it sometimes could bug your character, also you could zoom out and zoom in with num- and num+