C# FORM copy program crashes because of too much RAM usage

I’ve been trying to solve this problem, but I couldn’t find a solution.

When I’m copying the RAM usage is more than 2gb or more and than my laptop freezes.
What is can I do to free RAM?

This program sorts horizontal and vertical photoes so not a big deal and I’m aware that the code is not the best.

foreach (var srcPath in Directory.GetFiles(sourcePath))
            string Name = Path.GetFileName(srcPath);
            //Gets the file's format (like png or jpeg)
            string ext = Path.GetExtension(srcPath);

            bool allowFile = false;

            //This line examines the correct file's format, if it's not correct it won't copy it.
            if (ext == ".png" || ext == ".jpeg" || ext == ".jpg" || ext == ".mp4" || ext == ".PNG" || ext == ".JPEG" || ext == ".JPG" || ext == ".MP4")
                allowFile = true;

            Image img = Image.FromFile(srcPath);

            int width = img.Width;
            int height = img.Height;

            if (allowFile)
                if (height > width)
                    File.Copy(srcPath, pathString + "" + Name , true);
                    File.Copy(srcPath, pathString2 + "" + Name, true);
                //Copy the file from sourcepath and place into mentioned target path,                    

Source: Windows Questions