Reading package lists... Done
W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://extras.ubuntu.com precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 16126D3A3E5C1192

W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/precise/Release

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/main/source/Sources  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/restricted/source/Sources  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/universe/source/Sources  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/multiverse/source/Sources  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/main/binary-amd64/Packages  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/restricted/binary-amd64/Packages  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/universe/binary-amd64/Packages  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/multiverse/binary-amd64/Packages  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/main/binary-i386/Packages  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/restricted/binary-i386/Packages  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/universe/binary-i386/Packages  Hash Sum mismatch

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/multiverse/binary-i386/Packages  Hash Sum mismatch

W: Some index files failed to download. They have been ignored, or old ones used instead.