Could not download all repository indexes

Here the out put:

# deb cdrom:[Ubuntu 10.04 LTS _Lucid Lynx_ - Release i386 (20100429)]/ lucid main restricted
deb-src http://mirror.cs.umn.edu/ubuntu/ lucid main restricted #Added by software-properties
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://mirror.cs.umn.edu/ubuntu/ lucid main restricted
deb-src http://mirror.cs.umn.edu/ubuntu/ lucid multiverse universe #Added by software-properties

## Major bug fix updates produced after the final release of the
## distribution.
deb http://mirror.cs.umn.edu/ubuntu/ lucid-updates main restricted
deb-src http://mirror.cs.umn.edu/ubuntu/ lucid-updates restricted main multiverse universe #Added by software-properties

## 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://mirror.cs.umn.edu/ubuntu/ lucid universe
deb http://mirror.cs.umn.edu/ubuntu/ lucid-updates 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://mirror.cs.umn.edu/ubuntu/ lucid multiverse
deb http://mirror.cs.umn.edu/ubuntu/ lucid-updates multiverse

## Uncomment the following two lines to add software from the 'backports'
## repository.
## 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://us.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe 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 lucid partner
deb-src http://archive.canonical.com/ubuntu lucid partner

deb http://mirror.cs.umn.edu/ubuntu/ lucid-security main restricted
deb-src http://mirror.cs.umn.edu/ubuntu/ lucid-security restricted main multiverse universe #Added by software-properties
deb http://mirror.cs.umn.edu/ubuntu/ lucid-security universe
deb http://mirror.cs.umn.edu/ubuntu/ lucid-security multiverse

Could not download all repository indexes

The repository may no longer be available or could not be contacted because of network problems. If available an older version of the failed index will be used. Otherwise the repository will be ignored. Check your network connection and ensure the repository address in the preferences is correct.

Failed to fetch http://ppa.launchpad.net/user/ppa/ubuntu/dists/lucid/main/binary-i386/Packages.gz 404 Not Found
Some index files failed to download, they have been ignored, or old ones used instead.

after unchecking them.

Sorry, I did not get them all.
No errors now.

Thank you

Thanks wojox, that solved my question.

Just a note: I had this error, and all of my repositories were fine (and working on a separate Lucid install).

What I found was on the upgrade to 10.10 beta, my sources.list still had this at the top:

# deb cdrom:[Ubuntu 10.04 LTS _Lucid Lynx_ - Release amd64 (20100429)]/ lucid main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

What it needed was the following:

# deb cdrom:[Ubuntu 10.10 _Maverick Meerkat_ - Release amd64 (20100902)]/ maverick main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

That did the trick.

Just a note: I had this error, and all of my repositories were fine (and working on a separate Lucid install).

What I found was on the upgrade to 10.10 beta, my sources.list still had this at the top:

# deb cdrom:[Ubuntu 10.04 LTS _Lucid Lynx_ - Release amd64 (20100429)]/ lucid main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

What it needed was the following:

# deb cdrom:[Ubuntu 10.10 _Maverick Meerkat_ - Release amd64 (20100902)]/ maverick main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

That did the trick.

uncheck the ppa worked for me. thanks!