So i've recently started using LSPDFR and at first i had issues getting ragehook to work. Turned out that ragehook didn't want to work cause i was trying to install it into a duplicate game folder. As soon as i installed it into my main game, it worked perfectly. Now this isn't anything related to ragehook, i just wish to know how can i create a duplicate game (basically have GTA V installed twice on my PC) without having the problem of mods simply not working if i put them in the duplicate game folder? Do i have to rename the main folder or something? I just want to make sure that i have a clean installation of the game at any time and not have to worry about some mod file slipping by my eye and having it while playing Online. Any help would be appreciated! 

If you have another hard drive, its as easy as copy the main GTA V folder and paste it onto another drive.

A good idea is to have a normal GTA V copy (one that isnt modded at all) and one copy that you know worked 100% with any crashing errors etc. And finally have the copy you use to play the game on your main drive.

If you dont have another drive available, just do the same but rename the folder to something that the game wont look for, like "GTA V Backup"

I have hooked up, formatted and set as storage my previous HDD that i disconnected once i bought a new one. It is ~5 years old so i am concerned about it's performance, but i guess we will have to see. The game is copying right now. 

Nope, didn't work. RAGEHook still refuses to load if not in the main game directory.. If there was only a way to install the game twice..

you'll have to rename your original Grand Theft Auto V folder to something else, then rename the copied folder to the original folder name... or edit the registry key.