Originally posted at: http://www.anotherurl.com/library/intellisense.htm

Intellisense
The Intellisense feature in the Microsoft Development Environment need some cajoling to display parameter comments from class libraries.

The problem
You diligently create summary comments, but they are not displayed by Intellisense when you're editing code in other projects.

IntelliSense works correctly if you're working within the same project, but not other projects within the same solution.

The solution
The class library project must generate an XML Documentation File.

Go to the assembly project (DLL Library) properties within the solution
Change Configuration Properties. Set Configuration to "All Configurations". Go to Build | XML Documentation File.
Set this field to exactly the same name as the assembly, adding the extent “.xml”. The name must match the DLL name or IntelliSense will not find it!
Perform a “Rebuild Solution”. The environment will create an XML Documentation File, and copy it to the start up project bin directory, along with the associated assembly dll.
Close the Microsoft Development Environment. Yes, close it.
Run the Microsoft Development Environment...…and all should be fine. IntelliSense will now correctly display all summary comments