Trying to view saved HTML’s and I get this “Some pictures have been blocked to help prevent the sender from identifying your computer.” Why?

So I'm trying to make a signature for my e-mails (Yahoo, Live, Outlook, Gmail, etc) and well the HTML that I make and save isn't showing up in Explorer! Not Internet Explorer, Just the Explorer (File Browser). i.e. I saved the HTML to the desktop, So I go Start Menu>(user)> Desktop>"HTML" And when I click the HTML to view the preview off to the right side, It does not show up and simply states "Some pictures have been blocked to help prevent the sender from identifying your computer." It's a white box and an "x."When I try to put the signature into one of the e-mail clients, it appears the same way in a "New E-mail." i.e. I go into Windows Live Mail>Options>Mail>Signatures>Browse for HTML Doc and I insert my HTML Doc that I recently made. Everything there checks out alright until I go and make a new e-mail. Where the signature is supposed to be is just a white box. I guess what I'm asking is, How can I fix this?? I need those signatures ASAP