How to find version of an application installed using c#

Question

How to find version of an application installed, using c#. Is there a way to know component id of application?

EDIT: I need to get version of an already installed application.This is required for generating the diagnostics report on users machine.

Example:Version of Outlook 2007 installed on a user's machine

Answer 1

FileVersionInfo.GetVersionInfo("some.dll");