Sometimes we will get nice Images from Web as Icons. But we can’t use these Images as application icons in .Net, because the .Net supports *.ico(Icon) format only. This code will convert an Image to Icon using C#. It is written .Net Framework 3.5, but it should work in .Net 2.0. It supports Images upto size 128×128. And supports various image formats(*.jpg,*.gif, *.png. *.bmp).

using System;
using System.Drawing;
using System.IO;

string fileName, newFileName;
fileName = "C:\Sample.jpg";
newFileName = Path.ChangeExtension(fileName, ".ico");
using (Bitmap bitmap = Image.FromFile(fileName, true) as Bitmap)
{
    using (Icon icon = Icon.FromHandle(bitmap.GetHicon()))
    {
        using (Stream imageFile = File.Create(newFileName))
        {
            icon.Save(imageFile);
            Console.WriteLine("Converted - {0}", newFileName);
        }
    }
}

Code it pretty self explanatory. Let me know if you have faced any issues.