If your website is already online, make sure that you have transferred not only the HTML document with the image source code, but also the image itself. For example, if you are trying to embed <img src="C:\My Documents\Pictures\mydog.gif" alt tag="My Dog" /> make sure that the image file is within the website folder you are trying to upload. Therefore, you will have to copy it to your website folder, and place it into a folder named, for example, Images (you may have to create this yourself). This should be located very close to the top of the site's folder. You will have to change the code as well. Open your HTML document again, and simply replace the destination of the image source. For example, <img src="C:\My Documents\Pictures\mydog.gif" alt tag="My Dog" /> will become <img src="C:\My Website\Images\mydog.gif" alt tag="My Dog" />

Hope this helps.