I installed tomcat 5.0 on my machine. everything was ok, the server also strted. but when i make folowing changes
Configure Tomcat. Download the software. Go to http://tomcat.apache.org/download-55.cgi and download and unpack the zip file for the current release build of Tomcat 5.5. Using Tomcat with JDK 1.5 (Java 5) is preferred, but if you use JDK 1.4, you have to also download and unpack the "Compat" zip file. The the preconfigured Tomcat version already contains the "Compat" files and can be used with either Java 5 (1.5) or Java 1.4. Set the JAVA_HOME variable. Set it to refer to the base JDK directory, not the bin subdirectory. Change the port to 80. Edit install_dir/conf/server.xml and change the port attribute of the Connector element from 8080 to 80. Turn on servlet reloading. Edit install_dir/conf/context.xml and change <Context> to <Context reloadable="true">. Enable the invoker servlet. Go to install_dir/conf/web.xml and uncomment the servlet and servlet-mapping elements that map the invoker servlet to /servlet/*. Change the DOS memory settings. If you are on Windows 98/Me and get an "Out of Environment Space" error message when you start the server, right-click on install_dir/bin/startup.bat, select Properties, select Memory, and change the Initial Environment entry from Auto to at least 2816. Repeat the process for install_dir/bin/shutdown.bat. Only needed for Windows 98 and ME; not necessary on recent versions of Windows. Set the CATALINA_HOME variable. Optionally, set CATALINA_HOME to refer to the top-level Tomcat installation directory. Not necessary unless you copy the startup scripts instead of making shortcuts to them. Use a preconfigured Tomcat version. Optionally, use a version of Jakarta Tomcat that has all of the above changes already made, and has the test HTML, JSP, and servlet files already bundled. Just unzip the file, set your JAVA_HOME and CLASSPATH variables, and you are ready to go
Instead of pasting the installation instructions (which branch off cover more than one configuration, depending on the user's needs), can you describe what you did when installing? How are you starting Tomcat? How do you know it's not starting? What is happening? Did you look in the tomcat/logs directory to see if any errors are being reported?