The presets for DataAssist should be located in your user's configuration folder for Dreamweaver under:
Configuration/Shared/WebAssist/DataAssist/XML
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.