Q:

Do I need the Application Server role for a web server? 

I've just got a Windows Server 2008 which will work as a web server.  It has two roles in the Server Manager, one is Application Server (which includes Web Server (IIS) in its Role Services) and the other role is Web Server (IIS).  Do I need the Application Server role?  Can I remove it? 

A:

The Web Server (IIS) Support in the Application Server role services is there to provide integration with IIS to allow you to host applications using technologies such as WCF.  
If your application is just a plain ASP.NET/ASP/CGI/etc app and you're not utilising COM+, HTTP activation, Distributed Transactions then you can go ahead and safely remove this role.