From: Brian Piotrowski
Are there any free / built-in programs I can use to analyze the
400 to see where and when these bottlenecks occur?
I've never seen a tool that was good a pinpointing bottlenecks. On the other hand, if you think it would help to monitor performance of Web applications, Microsoft offers a couple free tools. Fiddler shows response times for each Web resource accessed. Just start Fiddler, then point IE to your Web site. Web Stress Tool allows you to record scripts, stress sites by simulating multiple users, and report response times.
They may not pinpoint bottlenecks, but they let you know which requests consume more time.