I suggest that you simplify the process of debugging this issue by setting a background colour in the css and see if that works.
If it doesn't, you know that the css isn't being read. Find out why not.
If the background colour change works, add the background image to the css, and see it that works.
If not, it suggests an image file access issue.
I've never tried to run apache on windows but I wonder about relative file paths, case sensitivity of filenames or possibly user permissions causing problems.
