What is w3wp.exe?

katie77 picture katie77 · Oct 19, 2011 · Viewed 217.7k times · Source

I have a WCF service running under a service user on my local system. Every time I try to debug it is giving me a message Attach Security warning.

In Visual Studio, by default (even without attaching), I get this error:

Attaching to this process can potentially harm your computer. If the information below looks suspicious or you are unsure, do not attach to this process

Name: C:\Windows\System32\inetsrv\w3wp.exe

What is w3wp.exe? According to a Google search, I think it is related to IIS. But what does it do? What setting should be changed so that this won't give this message everytime I try to debug on my local system?

Answer

Chris Kooken picture Chris Kooken · Oct 19, 2011

An Internet Information Services (IIS) worker process is a windows process (w3wp.exe) which runs Web applications, and is responsible for handling requests sent to a Web Server for a specific application pool.

It is the worker process for IIS. Each application pool creates at least one instance of w3wp.exe and that is what actually processes requests in your application. It is not dangerous to attach to this, that is just a standard windows message.