title: VirtualBox won't run win10: Failed to open a session for the virtual machine w10. Result Code: NS_ERROR_FAILURE (0x80004005)
body: <p>Ok so I want to get a virtual machine with Windows so I can download applications only on Windows (Not on OSX (I'm on Big Sur 11.2.3 by the way)), so I downloaded VirtualBox, then downloaded the Windows thing which apparently I have to (as seen in one of the pics) (you can tell I have hardly any experience with vms), then I created a new vm in the VirtualBox app, and left all the default settings except for the type of hard drive (which is also in one of the pictures), then I clicked <code>Start</code> and it asked me to add a 'virtual optical disk file', so I clicked on the folder button then clicked <code>add</code> in the top left, and it gave me this error code:</p>
  <pre><code>Failed to open a session for the virtual machine w10.
  
  The VM session was aborted.
  
  Result Code: NS_ERROR_FAILURE (0x80004005)
  Component: SessionMachine
  Interface: ISession {c0447716-ff5a-4795-b57a-ecd5fffa18a4}
  
  </code></pre>
  <p>as you can also see in one of the pictures below. Also, when I leave the screen for a couple of minutes right before I click on the previously mentioned <code>add</code> button, this appears:
  <a href="https://i.stack.imgur.com/p0nFt.png" rel="noreferrer"><img src="https://i.stack.imgur.com/p0nFt.png" alt="loading screen which does nothing" /></a></p>
  <p>but I tried just leaving it to load, and nothing happened. I have tried uninstalling using the uninstall tool twice, rebooting my Mac, etc etc, and yes I have allowed everything I need to in the <code>Security</code> settings. I'm not installing it on a moderator account, but the Windows 10 virtual optical disk file is in <code>Documents</code> which the account I'm on has read and write access to, and obviously the actual VM is in applications.</p>
  <p>Thanks so much!
  Here's the previously mentioned image of the one changed setting:
  <a href="https://i.stack.imgur.com/7cO1Z.png" rel="noreferrer"><img src="https://i.stack.imgur.com/7cO1Z.png" alt="changed setting" /></a></p>
  <p>And here's the pic of the Win10 64-bit I had to install:
  <a href="https://i.stack.imgur.com/x4zrY.png" rel="noreferrer"><img src="https://i.stack.imgur.com/x4zrY.png" alt="win10" /></a></p>
  <p>thanks everyone!</p>