Context initialization failed: Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/mvc]
Offending resource: ServletContext resource [/WEB-INF/dispatcher-servlet.xml]
1. Just to be clear is the xml you have posted your /WEB-INF/dispatcher-servlet.xml? That is the one causing the problem so make sure the spring mvc namespace is declared there.
2. After you have tried #1, What version of Spring do you have on your classpath? You are specifying 3.0 in your XSD.
3. Are you building your project with Maven? Make sure you are not pulling in multiple versions of Spring. Try running a mvn dependency:tree from the command line and make sure all the Spring versions look correct and you are not pulling in old versions as transitive dependencies.