I consider myself an intelligent, capable person, but I am about to lose my mind.  I've tried to upgrade DNN 2.1.2 to DNN 3 about 15 times.  Everytime, except once when I upgraded in debug mode with the source itself, my upgrade attempt results in nothing but IE continuously redirecting to localhost over and over again.  ARGH!!!!

I am hitting the upgrade at http://localhost/rt/.  My portal table includes alias "localhost/rt", about third in the list.

Here are the steps I took:

1.  Copied entire dnn 2.1.2 folder over to my webroot/rt.
2.  Copied db
3.  Modified web.config to point to the copied db
4.  Verified that http://localhost/rt/ works properly.
5.  Copied dnn3 files on top of my webroot/rt files.
6.  Updated the web.config to point to my copied db, left MachineKeys alone since no such setting exists in my 2.1.2 webconfig.
7.  Hit http://localhost/rt/, upgrade proceeds successfully.
8. "Click here" to access my portal, results in continuous redirection.

Please help before I pull out all my hair.