What the OP hasn't made clear is whether or not they verified that the .iso image for Tails was correct or not. Ideally, one should verify the Tails .iso image against its' detached PGP signature, as follows: gpg --verify tails-i386-0.15.iso.pgp tails-i386-0.15.iso  gpg: armor header: Version: GnuPG v1.4.12 (GNU/Linux)gpg: Signature made Mon 26 Nov 2012 08:45:14 AM EST using RSA key ID BE2CD9C1gpg: NOTE: signature key BE2CD9C1 expired Sat 06 Oct 2012 05:29:24 AM EDTgpg: Good signature from "Tails developers (signing key) <tails@boum.org>"gpg:        aka "T(A)ILS developers (signing key) <amnesia@boum.org>"gpg: WARNING: Using untrusted key!gpg: binary signature, digest algorithm SHA512NC