Im stuck and my website is a mess

I decided to fix a few things on my site. When I went to upload the new site no matter what I do its missing dependent files. Like the main opening graphic is gone and the background is gone. I changed nothing and I have them still in the same places they where before. But nothing seems to load right. I tried deleting and re upping it from a backup but no luck.
Sites here

Bad references to image files: URLs to local files instead of relative or to the domain.

wrapper { background-image: url("file:///C|/Users/mark/Desktop/"); background-repeat: no-repeat; height: 1920px; margin: auto; text-align: justify; width: 945px;

How would I go about fixing that?

use relative links.