Need to issue a SHA256 certificate from a CA with a SHA1 chain

I have searched a number of forums to find the answer to this.

My CA is based on Windows Server 2008 SP2.

I have found many answers which state that you need to edit the registry in order to get the CA to issue SHA256 certificates, but if this is the case then why is there a Hashing Algorithm setting on the Cryptography tab of the Certificate templates.

This does not appear to do anything.

Any ideas anyone?

Thanks

JF