virtualbox.org

I have installed 2.1.0 version. The online registration always return an error message:

Failed to connect to the VirtualBox online registration service due to the following error:

HTTP request failed.

Now it's unable to use the program. What should I do?

Can't you just cancel the Registration when the window appears? I don't remember registering my virtualbox installation and i'm still using it.
Registration is voluntarily.

Maybe you are right. I would like to use Ubuntu under Vista. If I cancel the registration form and I try to boot from iso image the following error appears: VERR_ACCESS_DENIED

What more info do you get for that access denied?

I have uninstalled the expired McAfee firewall, and now everything is working. Thanks for the posts.