Не удается подключиться к ubuntuarchive.hnsdc.com, как установить g ++? [дубликат]

При запуске sudo apt-get update я получаю следующие ошибки:

Err archive.ubuntu.com quantal InRelease
Err archive.ubuntu.com quantal-updates InRelease
Err archive.ubuntu.com quantal-backports InRelease
Err archive.ubuntu.com quantal-security InRelease
Err archive.ubuntu.com quantal Release.gpg
  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
Err archive.ubuntu.com quantal-updates Release.gpg
  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
Err archive.ubuntu.com quantal-backports Release.gpg
  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
Err archive.ubuntu.com quantal-security Release.gpg
  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
Reading package lists... Done
W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal/InRelease  
W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-updates/InRelease  
W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-backports/InRelease  
W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-security/InRelease  
W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal/Release.gpg  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-updates/Release.gpg  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-backports/Release.gpg  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-security/Release.gpg  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
W: Some index files failed to download. They have been ignored, or old ones used instead.

Я использую Ubuntu 12.04. Это команда, которую я используется после установки Ubuntu из установщика окна. Я уверен, что мой ноутбук подключен к Интернету. Что я могу сделать сейчас?