Host-only networking stopped working after the VirtualBox 4.04 upgrade. After searching far and wide, I found this post that recommending reinstalling the whole shooting match....viola, I'm back in business!
I have a few virtual machines that I wanted to skip the logon step.
This site show exactly how to do it with a few registry tweaks. Its a time saver!
syntax I'll never remember.
C:\Program Files\Sun\VirtualBox>VBoxManage clonehd "base.vdi" "myNewBox.vdi"