I have a certificate (sccm client certificate) that I need to update security group permissions on. After I update the appropriate permissions to the certificate template, do I need to reissue the certificate? If I do, do I need to delete the original certificate that was issued prior to reissuing the certificate template with the udpated permissions? Thanks ahead!

If I understand your question correctly, you are wondering if changing the template security affects existing certificates. If that is the question, then the answer is 'no'. The security tab only controls which security priciples (computers, groups and users) can request and enroll certificates. If you change any other parameters on the certificate template it will not be reflected on the existing certificates, but will for any new ones. It is best to think of the certificate templates as cookie cutters. When you create a certificate with one, it will have all the existing characteristics it had when created. If I change the cookie cutter, it does nothing to the cookies that are already baked.fr3dd