Update errors: 404, "E: Unable to parse package file " [duplicate]

Possible Duplicate:
How can I fix a 404 Error using a PPA?

Whenever i try to install or update anythin in ubuntu 11.10 i am getting this list of errors.

Some restricted , universal and main packages show the result failed to fetch or 404 error or check your internet connection.

I have updated several times but the problem persists.Do i have to add / remove something from my source list please help.

This is the list of errors i am getting.

This is my source list

i changed the server so now only one errors remains

E: Unable to parse package file  /var/lib/apt/lists/partial/mirror.cse.iitk.ac.in_ubuntu_dists_oneiric-security_multiverse_i18n_Index (1)

where mirror.cse.iitk.ac.in is the new mirror i am using.

1 Answer

Is this an updated install ?

Verify that your sources.list contains one uncommented http or ftp source for each branch you need, and delete the downloaded lists (in /var/lib/apt/lists/partial/) to start fresh.

W:GPG error: oneiric Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5A9A06AEF9CB8DB0

This means you have a custom PPA loaded which is not valid for this version - I suspect you upgraded from an earlier version.