Well actually they are not written correctly.
I assume you were doubleclicking the file from explorer! That does not use Apache to serve the page and therefore your previous tests were null and void.
Unless you are familiar with virtual hosts, you should have your site code in a folder under c:\wamp\www for example c:\wamp\www\project1.
So you would have this kind of structure
c:\wamp\www\project1 (containing your .php pages)
\project1\images (containng images)
\project1\javascripts (containing any js scripts)
\project1\styles (containing any css scripts)
The proper format for a url used from a css file in the style folder would then be:
html, body {
background-image: url("/images/background.jpg"
}
Remember files addressed from a css file have to be relative to the location of the css file.
And in your HTML/PHP file located in the project1 folder, the urls for example for an img tag would be
<img src="images/mylittlepicture.jpg"
}
In short, dont use explorer to launch your web pages, especially if they contain php script as php scripts will only run if you use the browser to launch the site and therefore Apache which has the knowledge to pass the php parts of a page to the php interpreter. Explorer launched pages do not.