I'm surprised this discussion is still going on, I already told you what you needed to know in my my last post, including the link to the "Moving" howto.
There is no special mystery here. Everything you do in a VM is separate from the host. If the VM files (e.g. VDI, .vbox) are not stored on host PC then no amount of examination of the host PC can reveal what you were doing in the guest.
The host PC is not the only place a snooper could look: but we also already covered what you can do about that.