My update manager doesn't update [duplicate]

Question

Possible Duplicate:
What is the easiest way to resolve apt-get BADSIG GPG errors?

Well, I've installed Ubuntu 11.10 from a couple of weeks & tried to update my software but it doesn't work.

Each time I'm trying to update with the update manager, there's an error for

"Requires installation of untrusted packages

The action would require the installation of packages from not authenticated sources."

Tried everything in the questions before, from my network connection & it was good & tried to see the archive packages and this is what I've

W: GPG error: http://eg.archive.ubuntu.com oneiric Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>

W: Failed to fetch http://ppa.launchpad.net/sevenmachines/flash/ubuntu/dists/oneiric/main/source/Sources 404 Not Found

W: Failed to fetch http://ppa.launchpad.net/sevenmachines/flash/ubuntu/dists/oneiric/main/binary-i386/Packages 404 Not Found

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

Don't know what's the problem ?!!!

Answer 1

Ah.. the classic BadSig error...

Here is the one-shot solution:

http://maketecheasier.com/solve-badsig-error-in-ubuntu/2012/01/13

Answer 2

That's a problem with the mirror. There's nothing you can do about it. If you want to, you can switch to another mirror temporarily though. The fastest way of doing that, is to open a terminal and run the following: sudo sed s/eg.archive/archive/ --in-place /etc/apt/sources.list and then sudo apt-get update. That will switch to archive.ubuntu.com instead.