1. Check the general requirements.
2. Check Corn's requirements.
3. Download the Corn GUI (graphical user interface)
4. Download Corn versions 0.30WIP, 0.29 and 0.20
5. Download the latest Corn INI for each version.
6. Download the Preview BMPs (optional).
7. Check that you have at least one ROM!
8. Extract one* version of Corn into a folder.
9. Extract the Corn GUI into the same folder.
10. Extract the correct INI into the same folder.

If you are ever prompted to overwrite existing files, say yes.

*Which version of Corn should you use? It depends on which games you want to play! Check the compatibility lists. I suggest making seperate installations of Corn to give you the most choice. I realise this situation isn't ideal...

Now you need to configure Corn...