Jak upgradovat na Hwe 12.04.5?

Můj systém:Zcela nový Dell OptiPlex XE2 s 12.04 předinstalovaným společností Dell.

Všechny bezpečnostní aktualizace jsem použil přes správce aktualizací. Nyní mi Správce aktualizací říká toto:

Kliknu na tlačítko Upgrade a zobrazí se tato chyba:

Jak to napravím a upgraduji svůj systém na nejnovější verzi 12.04.5?

/etc/apt/sources.list

# deb cdrom:[Ubuntu 12.04 _Precise_ - Build amd64 LIVE Binary 20130203-13:50]/ precise main

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://us.archive.ubuntu.com/ubuntu/ precise main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ precise main restricted

## Major bug fix updates produced after the final release of the
## distribution.

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ precise universe
deb-src http://us.archive.ubuntu.com/ubuntu/ precise universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://us.archive.ubuntu.com/ubuntu/ precise multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.

deb http://security.ubuntu.com/ubuntu precise-security main restricted
deb-src http://security.ubuntu.com/ubuntu precise-security main restricted
deb http://security.ubuntu.com/ubuntu precise-security universe
deb-src http://security.ubuntu.com/ubuntu precise-security universe
deb http://security.ubuntu.com/ubuntu precise-security multiverse
deb-src http://security.ubuntu.com/ubuntu precise-security multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu precise partner
# deb-src http://archive.canonical.com/ubuntu precise partner

## Uncomment the following two lines to add software from Ubuntu's
## 'extras' repository.
## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
# deb http://extras.ubuntu.com/ubuntu precise main
# deb-src http://extras.ubuntu.com/ubuntu precise main

/etc/apt/sources.list.d/precise-dell.list

deb http://dell.archive.canonical.com/updates/ precise-dell public
deb-src http://dell.archive.canonical.com/updates/ precise-dell public

/etc/apt/sources.list.d/precise-oem-sp1.list

deb http://oem.archive.canonical.com/updates/ precise-oem-sp1 public
deb-src http://oem.archive.canonical.com/updates/ precise-oem-sp1 public

Přijatá odpověď:

Máte povolené aktualizace zabezpečení, ale ne běžné aktualizace.

Související:Oddíly zmizely po výpadku napájení při instalaci v Ubuntu?

Ujistěte se, že jste aktivovali přesné aktualizace ve zdrojích softwaru, jak je vysvětleno na této wiki stránce.

Poté znovu postupujte podle pokynů na https://wiki.ubuntu.com/1204_HWE_EOL_OEM