We just released another Fix it Knowledge Base (KB) article. This Fix it addresses the following scenario. You install Adobe Dreamweaver on a Windows Vista-based computer. Additionally, you accept the option to make Dreamweaver the default editor for XML files. In this scenario, Windows Vista Help and Support stops working.
When you try to run Windows Vista Help and Support, you receive the following error message: “Internet Explorer cannot download / from windows. Internet Explorer was not able to open this Internet site. The requested site is either unavailable or cannot be found. Please try again later.”
This Fix it modifies the Windows Vista registry as described in KB937491.