Don't what what you mean by "screams" but there is no way you can run a server off a P4 with 768MB or RAM. Windows may boot OK, but if you actually use it for work, you will run into some major issues.
I thought there was something I was missing as I read it also. Later I found this...
"A Web server can be either a computer program or a computer running a program that is responsible for accepting HTTP requests from clients, serving back HTTP responses along with optional data contents, which usually are web pages such as HTML documents and linked objects on it. An application server is the kind of software engine that will deliver various applications to another device. It is the kind of computer found in an office or university network that allows everyone in the network to run software off of the same machine."http://www.diffen.com/difference/Application_Server_vs_Web_Server
It goes into more detail there too - just clarifying since I learned something I was not aware of