Because it's my half term break, I went to visit my relatives. The night before I left I went on Steam and clicked on uninstall, and reinstalled my game. I came back a couple of hours ago to find it wasn't uninstalled, and my ENB (which was causing all the problems resulting in a reinstall) was still there, along with all the scripts. I don't know if other Steam users experience this as well, but I do with GTA IV only. So, here's the fix::

 

 

The workaround for this is pretty easy actually, you just have to go into your main directory, navigate to your SteamApps folder>common> and then select Grand Theft Auto IV - NOT THE GTAIV FOLDER INSIDE OF IT!!!. Once that is complete, even with Steam running, the play button will turn to install and you will be able to reinstall your game. I hope this helped people because I experience this issue a lot with Steam. 

The easy way to reinstall your game is to delete everything related to IV, including what is in the steam folder. (I use steam too) then uninstall the game. It ensures no files are left behind which may corrupt your game or cause problems. 

The easy way to reinstall your game is to delete everything related to IV, including what is in the steam folder. (I use steam too) then uninstall the game. It ensures no files are left behind which may corrupt your game or cause problems.