You are a network administrator for your company. You need to test a new application. The application requires two processors and 2 GB of RAM. The application also requires shared folders on the application server and requires the installation of software on the client computers. You create the test plan. You assemble a server in the test lab. You install Windows Server 2003， Web Edition on theserver. You install the application on the server. You install the client software components for the application on 20 client computers in the test lab. You test the application. You discover that only some of the client computers can run the application. You turn off the client computers that ran the application successfully， and you test again. The client computers that failed in the first test now run the application successfully. You need to identify the cause of the failure and update your test plan. What should you do？ （）

A. Increase the Maximum number of worker processes to 20 for the default application pool.
B. Use Add or Remove Programs to add the Application Server Windows component.
Change the Application pool identity to Local Service for the default application pool.
D. Change the test server operating system to Windows Server 2003， Standard Edition or Windows Server 2003， Enterprise Edition.