Q:
W: GPG error: http://mirror.switch.ch squeeze Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY AED4B06F473041FA NO_PUBKEY 64481591B98321F9
W: GPG error: http://security.debian.org squeeze/updates Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY AED4B06F473041FA
W: GPG error: http://mirror.switch.ch squeeze-updates Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY AED4B06F473041FA
W: You may want to run apt-get update to correct these problems
A:
apt-get install debian-archive-keyring