I tried the steps exactly, and yet I still get the message "Internet Explorer cannot display the webpage".
You didn't specify at which step you got this error message. There were several steps in the process.

But, I think Jerry may have hit upon a clue. Make sure the filenames have no spaces, AND end in .jpg (for jpeg files) Don't try uploading BMP or other images files. They don't get handled well in the forum software.

Ray