W: GPG error: http://www.backports.org etch-backports Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EA8E8B2116BA136C
W: GPG error: http://www.debian-multimedia.org etch Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 07DC563D1F41B907
W: You may want to run apt-get update to correct these problems
E: Some index files failed to download, they have been ignored, or old ones used instead.

Hey thanks, I have been on google for the past couple of hours though so my advice is if you don't want to help don't reply dude I still get this btw from following many answers

gpg: key 437D05B5: public key "Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>" imported
gpg: Total number processed: 1
gpg: imported: 1
gpg: no ultimately trusted keys found


and also

sean@Debian:/etc/apt$ gpg --import pubkeysomething gpg: key 437D05B5: "Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>" not changed
gpg: Total number processed: 1
gpg: unchanged: 1
sean@Debian:/etc/apt$ gpg --armor --export 437D05B5 | apt-key add - gpg: can't open `/etc/apt/trusted.gpg'
gpg: keydb_get_keyblock failed: eof
gpg: no writable keyring found: eof
gpg: error reading `-': general error
gpg: import from `-' failed: general error
sean@Debian:/etc/apt$

You neglected to run the apt-key command as root.

My advice to you is to read this.

I am helping, be it in my own way. Learning to help one's self goes a long way.

The instructions are right on the backports.org page, if you can't be bothered to READ do you seriously expect people to be able to help you?

Debian Backports