title: R cannot be resolved to a variable without doing anything to the project
body: <p>I am getting the error "R cannot be resolved to a variable" that many people seems to be getting.  However, none of the answers that I have seen has worked for me.  I've gone to the extreme basic and created a helloworld project, with all default settings.  The "R cannot be resolved to a variable" error is created instantly, and I cannot see what is wrong... no xml errors, all lowercase in /res/ folder, no difference in AndroidManifest.xml.</p>
  
  <p>For reference, the code on MainActivity.java is:</p>
  
  <pre><code>package com.test.helloworld;
  
  import android.os.Bundle;
  import android.app.Activity;
  import android.view.Menu;
  
  public class MainActivity extends Activity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.main, menu);
          return true;
      }
  </code></pre>
  
  <p>}</p>
  
  <p>Is there something wrong with eclipse setting?
  I'm using Windows 7 64-bit</p>