Thank you for your help. After some extensive research online. I discovered how to find the file.

I have tried everything I can on this page. I cant find this ... %appdata%\factorio, in any folder though. I also have the show hidden folders clicked as well.

When I try and load the game it stops at Building Prototype. and then gives me.. Error in assignID, technology with name 'laser-turrents' does not exist. I've deleted all files and redownloaded the game but it still does it.