title: Vagrant up error in headless Ubuntu: The guest machine entered an invalid state while waiting for it to boot
body: <p>I need to install vagrant in headless ubuntu (Ubuntu 12.04.2 LTS-64 Bit). Vagrant ver-v1.3.0 and Virtual box- 4.2.18. After adding the vagrant package box, when I am giving &quot;vagrant up&quot; command, am getting the following error:</p>
  <pre><code>Bringing machine 'default' up with 'virtualbox' provider...
  [default] Clearing any previously set forwarded ports...
  [default] Creating shared folders metadata...
  [default] Clearing any previously set network interfaces...
  [default] Preparing network interfaces based on configuration...
  [default] Forwarding ports...
  [default] -- 22 =&gt; 2222 (adapter 1)
  [default] Booting VM...
  [default] Waiting for machine to boot. This may take a few minutes...
  The guest machine entered an invalid state while waiting for it
  to boot. Valid states are 'starting, running'. The machine is in the
  'poweroff' state. Please verify everything is configured
  properly and try again.
  </code></pre>
  <p>When I searched this error message, I found the need to modify your BIOS to enable VT-x features. But I don't know, how to do it as it is a headless ubuntu remote server. Also am not sure whether enabling VT-x will fix the problem.</p>
  <p>Can someone help me with this?</p>