ComputingConfidence

You get a message like this:

"W: GPG error: http://ppa.launchpad.net hardy Release...."

In a terminal do the following do command lines while changing to the actual key from the message:

gpg --keyserver subkeys.pgp.net --recv FCA4A9D8F45955CE

gpg --export --armor FCA4A9D8F45955CE | sudo apt-key add -

The action would look something like this:

carl@cjfh3:~$ gpg --keyserver subkeys.pgp.net --recv FCA4A9D8F45955CE

gpg: requesting key F45955CE from hkp server subkeys.pgp.net

gpg: key F45955CE: public key "Launchpad PPA for bortis" imported

gpg: Total number processed: 1

gpg:               imported: 1  (RSA: 1)

carl@cjfh3:~$ gpg --export --armor FCA4A9D8F45955CE | sudo apt-key add -

OK

carl@cjfh3:~$ 

After that you should be okay.