There is a tool Process Explorer that can help you to explore all the process and the resource used....
Inetinfo.exe (IIS 6.0)
When IIS 6.0 runs in worker process isolation mode,Inetinfo.exe is a
user-mode component that hosts the IIS metabase and that also hosts
the non-Web services of IIS 6.0, including the FTP service, the SMTP
service, and the NNTP service.
Inetinfo.exe depends on IIS Admin service to host the metabase. When IIS 6.0 runs in IIS 5.0
isolation
mode, Inetinfo.exe functions much as it did in IIS 5.0. In IIS 5.0
isolation mode, however, Inetinfo.exe hosts the worker process, which
runs ISAPI filters, Low-isolation ISAPI extensions, and other Web
applications.
In IIS6.0, regardless of the application
isolation mode used, the services that run in Inetinfo.exe run as
dynamic-link libraries (DLLs) under the Local System account. Because
a Local System account allows users access to every resource on the
local computer, use caution when you run services in Inetinfo.exe,
especially on computers that provide services on the Internet.
From MSDN InetInfo