"The requested operation requires elevation"

Typical SharePoint 2010 install.  I had created all my domain users, set up my servers, and started installing the prerequisites.  When the first box in the farm restarted and the preparation utility came up, I was asked for credentials and provided them, only to be rejected.  At first I thought it was a standard "access denied" error, but a look at the fine print revealed the error titling this post.

I tried Run As Administrator; still no success.

Eventually I realized that I was signed in as the farm account, though I had not yet made it a local administrator.  I right-clicked Computer Management, ran THAT with the proper credentials, made the farm account local admin, and all was right with the world.

Sometimes it's the little things.