Whonix
Whonix is an Anonymous Operating System.
...DNS leaks are impossible, and not even malware with root privileges can find out the user's real IP.
Whonix consists of two parts: One solely runs Tor and acts as a gateway, which we call Whonix-Gateway. The other, which we call Whonix-Workstation, is on a completely isolated network. Only connections through Tor are possible.
Whonix is produced independently of, and carries no guarantee from, The Tor Project.
For download:
https://www.whonix.org/wiki/Download