further details on Unable to save php file in dreamweaver.

I am taking a class in PHP. I am following instructions to set up my work environment in Dreamweaver. I am using an Imac, dual core, running snow leopard, and have loaded xampp onto my machine. Dreamweaver version CS3.

Class instructions say to set up my local site with following path: Applications/xampp/htdocs. My DW wants me to use : instead of /, so when I set up the local site, this is what my path looks like. Macintosh HD:Applications:XAMPP:xamppfiles:htdocs:
When I try to save my first page, as a .php, I get the following error message: Access to MacintoshHD:applications:XAMPP:xamppfiles:htdocs:hello.php was denied. I get this error message on both of my macs, so it is a problem in my path, not individual to my machine.

There is something wrong with my path, but I don't know what it is. I cannot create path with / instead of :, DW won't allow it. I tried creating a path exactly as instructed in the lesson, but that did not help. I don't know what I am missing because I am just starting so I don't know what to look for. Any thoughts? Thanks in advance....