you need to use quotes around the session.save-path value:
session.save_path = "C:\xampp\tmp"
and make sure that the path:
actually exists on the computer, if it has not been created, you need to create it.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.