by default, xamp should be installed ton the c drive at:
for this address to work:
the files should be at:
in your site settings in dreamweaver the first step is to set the local files location, set the local files to be saved at:
in the testing server section, use the local path:
and the Web URL:
most likely what is happening is that you have the local path to another location, or the testing server path to another location.
if the local path is to another location, the files need to be put before browsing to them
if the testing server path is to another location, that wont map with how xampp is configured.