You put inside img tag physical path you your image. Instead of that you should put virtual path (according to root of web application) to your image. This value depends on location of your image and your html page.
for example if you have:
/yourDir
-page.html
-66.jpg
in your page.html it should be something like that:
<img src="66.jpg" width="400" height="400" ></img>
second scenario:
/images
-66.jpg
/html
page.html
So your img should look like:
<img src="../images/66.jpg" width="400" height="400" ></img>