Get exception java.lang.ClassNotFoundException: org.apache.catalina.startup.Bootstrap when starting tomcat

I am trying to start tomcat from command line getting below error

C: \ Program Files \ Apache Software Foundation \ Tomcat 7.0 \ bin> java org.apache.catal ina.startup.Bootstrap

Exception on thread "main" java.lang.NoClassDefFoundError: org / apache / catalina / s tartup / Bootstrap

Caused by: java.lang.ClassNotFoundException: org.apache.catalina.startup.Bootstrap

at java.net.URLClassLoader $ 1.run (URLClassLoader.java:202)

at java.security.AccessController.doPrivileged (native method) at java.net.URLClassLoader.findClass (URLClassLoader.java:190) at java.lang.ClassLoader.loadClass (ClassLoader.java.307) at sun.misc.Launcher $ AppClassLoader .loadClass (Launcher.java:301) in java.lang.ClassLoader.loadClass (ClassLoader.java:248) Could not find main class: org.apache.catalina.startup.Bootstrap. Program window

Please suggest how to solve this.

Thank.