Back again. I am running SQL 2005 on a XP Pro machine. Here is what I did:

create master key encryption by password = 'Pufd&s@))%';

create certificate cert_sk_admin with subject = 'Certificate for accessing symmetric keys - for use by admin';

create certificate cert_sk_charles with subject = 'Certificate for accessing symmetric keys - for use by Charles';

create symmetric key sk_users with algorithm = aes_192 encryption by certificate cert_sk_admin;

The above command generates an error:

Msg 15314, Level 16, State 1, Line 1

Either no algorithm has been specified or the bitlength and the algorithm specified for the key are not available in this installation of Windows.

Any Ideas?

Thanks,

Phil.