An under utilized Microsoft tools that deserve a mention is Wfetch.  It is provided as part of the IIS  Resource kit and can be downloaded from Microsoft or from here.  This is an invaluable part of your IIS troubleshooting tool kit.

Wfetch is a great little tool to see HTTP headers as well as request and associate response traffic.

•Multiple HTTP verbs (GET, HEAD, PUT, DELETE, TRACE, POST, OPTIONS)
•Configurable host name
•Configurable TCP port
•HTTP 1.0 and HTTP 1.1 support
•Multiple authentication types (Anonymous, Basic, NTLM, Kerberos, Digest, Negotiate)
•Client-certificate support
•Multiple connection types (HTTP, HTTPS, PCT 1.0, SSL 2.0, SSL 3.0, TLS 3.1)
•Proxy support
•Advanced requests that are entered manually or read from a file
•On-screen and file-based logging