virtualbox.org

When I tried to start my virtual machine i received the following error:If upgraded recently(which I have)terminate all VMs and upgrade any extension packs.
As for terminate all VMs I simply moved them to trash but I do not understand the procedure for upgrading any extension packs(where to look and how to)I am somewhat of a newbie could you please help?

As for terminate all VMs I simply moved them to trash

I don't understand why you would do this. that is not what terminate means. You will kill those guests completely.
As for the extension pack How to install Extension Pack