updating to el c and replacing drive
 

i have updated snow leopard to Capitan on an external drive and still have a clone of the snow leopard. The internal drive has been dead for awhile and i am having it replaced. Capitan will be installed on the new internal drive by the repair guy. i intend to restore to the new drive the Capitan upgrade i already have because of a firewall program that survived the upgrade but can't be installed cleanly because of the new security protections. i understand that i need to download a SD update from your website. my question:

will those security protections prevent a smart update?
if i do a clean restore, should i wipe the internal disk using SD or would it be better to boot from the snow leopard clone and use disk utility to reformat?

Smart Update should work fine with your restoration: the blog post that discusses this issue was during the beta of El Capitan. Apple fixed the issue, and restorations work as expected.

That said, you should not copy El Capitan from Snow Leopard. That's not going to work. You need to use El Capitan or later. This is generally true: you shouldn't copy later versions from earlier versions: the OS's file system changes, and only the newer OS versions know how to deal with it properly.

As such, you'll want to migrate from the copy during first boot of the new install.

didn't do it on the first boot but it still worked like a charm. thanks for this program

Glad to hear you're all set.