Got stuck trying to run a C# script

Hello all, I’m a noob to github and coding outside basic website design and Matlab. I’ve been trying to run a script for about a week now, but I think I’m lost in the woods at this point and I won’t be finding my way out without some direction.

I want to use a script that extracts images from a certain file format. The project is comprised of a .cs file, a .bat file, and several .dlls. I’m running Windows 10.

I’m not sure I even understand how to do this, but so far, I’ve gotten the csc command to work from my command line (and the terminal), I’ve used visual studio and tried what I could understand to compile or run through that, and I’ve installed and attempted to get any results from cygwin (I have the gcc command but it’s not configured). Most of these throw an error, so I’m guessing none of those things were the correct option lol. The code is confirmed to be functional.

The error I see the most is “The type or namespace name ‘Tasks’ does not exist in the namespace ‘System.Threading’ (are you missing an assembly reference?)” which doesn’t make a lot of since from a working program, so I thought it might have something to do with my settings. There’s a line early in the .cs file “using system.threading.tasks” which I have gathered is an important piece of information…maybe? 

Any direction would be greatly apreciated, I’d really like to get this working but I’m a coding dummy and I’m pretty sure I’m just spinning my wheels.