Just a quick tidbit based on a question from a client today.
When you need to run a web test against a web site that uses Integrated Windows Authentication, you need to be able to set the credentials of the user for each test run.
To do this follow the steps below:
1. In your web test, select the root node.
2. In the Properties pane, enter a value for the Username property. This can be in the form domainuser. You can also bind to this property from a datasource.
3. In the Properties pane, enter a value for the Password property. As with the Username property, you can retrieve this value from a datasource.