If you receive a 404 Error, you can use the URL to identify the missing file. You can also identify missing images with their URL. If you have a missing image, Internet Explorer will display it as a red x. Right cicking the red x and selecting "properties" will give you the URL for that missing image.
If the URL looks like this, for example:
then you can find the folder that the missing file should be in at /public_html/stuff/goes/