Includes file references (html)

I'm looking for some help regarding use of includes files.

I'm setting up a basic html based site (i.e. not php, etc.).
I have a /includes folder that contains all of the referenced includes .htm files

This works great, as long as the site is set up under a sub-folder. But the includes references stop working if I set up the site under the root /web/ folder.

For example, the includes references work fine when using this structure:
/web/
/web/folder/index.htm
/web/folder/includes/

But, when using this structure, the include references fail:
/web/
/web/index.htm
/web/includes/

I'm somewhat of a html rookie ... Is there a server setting that I'm missing? Is there something about 'includes' references that I'm missing?

Any suggestions are appreciated.

Thanks.

It appears that you are using a relevant file path. If you are doing this, try placing two dots in front of the leading slash like this....

<!--#include file="../includes/file.html" -->

I think your file path is correct. Have you try to use xml for providing your file path. It may be useful for configure your file settings.