You can download the free extension manager from DMXZone and it will work: http://www.dmxzone.com/go/22670/dmxzone-extension-manager-for-dreamweaver/
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.