This article has been tested and confirmed on Windows 2003.  It will likely also work on other versions of Microsoft Windows, but has not been fully tested.

Problem:

When viewing Windows Task Manager, you may notice that the IIS process (w3wp.exe) is taking a lot of CPU or memory.  The problem is that discovering which web site is causing the high resource utilization is difficult to do.

Solution:

1. In Windows Task Manager's Process view, click on View and choose Select Columns
2. Check PID (Process Identifier)
3. Click OK
4. Find the PID of the process using too many resources
5. Open a command prompt
6. Type the following:
   1. cd \Windows\System32
   2. cscript.exe iisapp.vbs

The application pool causing the problem should show up under the list with the PID you have.  If multiple applications are running under the same application pool, you may need to split them up to discover which is the culprit.