Windows 7: virtualization

I recently scanned a text for Win 7 about how to virtualize a PC.

Is there a best recommendation for an app (free download, no beta version) that can detect if your PC (XP/Vista/7) has been virtualized?

Is your PC was virtualized, how does a use get out of it?

Is there a way to prevent from being virtualized?



Is there an app that can display if your PC is connected to an anonymous, remote VPN (even if the IP address is hidden say from a proxy server) or connected to a virtual network ?

If so, how does the user block/disable/disconnect?

I read from Maximum PC magazine, if one wishes to custom build a gaming PC and has to install the Windows Update - the author states to make sure you are behind a NAT.
How can one configure a NAT - Network Address Translation (hiding one's IP address from hackers) using Win 7?
The author did not state about using a router nor about configuring ICS nor about configuring Windows Firewall adv.

Also, is there a way to prevent from being scanned say from your ISP or hackers?
I know that hackers would secretly install a keylogger. Are there other ways?

How does a user protect all the services and registries?
Is the best way is to place a checkmark next to Deny: Full Control - no one has access, not even the user or Deny: Read Only?