Helen - are you using a website that allows you to link to the picture? It might be that your host doesn't allow it - thus the box with the question mark.
Or make sure you have at the beginning of the location. You also have to have the same thing at the end of the location address - the one at the end has to have a backslash in front of the "img" (I'd type it, but then it looks for a pic inbetween the two boxes and turns all of this writing in to a box with a question mark in it!)
From the file information the image is actually stored on your hard-drive and not a webpage. For you to show images on the forums you need to have them upload somewhere.
Your file size is fine and I just tried the format you recommended and it does not work for me either. In order to post images from your hard drive, your PC would need to be setup as a web server.