If you wish it to show up from within the My Computer folder by itself you can't do what it is you wish to do. That is reserved for drives and mechanical storage only.

There are some third party applications that will allow you to do amazing things with folders but I would not reccommend that you edit that area as it could cause undesired effects for listing your drives.....

What you could do is create a new partition on your drive and name it "files stored on this computer" It would show as a drive icon and not as a folder icon and you can make this partition fully shared if you wish!