This should help:

DotNetNuke Login is not working!! How am I going to get back in?

I tried this for the same problem, but I got this error:

  Description: HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable.  Please review the following URL and make sure that it is spelled correctly.

Requested URL: /OpenSesame.aspx

Server Error in '/' Application.

---

The resource cannot be found.

Am I putting it in the wrong place? It's at the same level as web.config, right? Right under /dotnetnuke (or whatever your directory name is called--mine is different).

Here is my site:

http://alvincountryclub.com/dotnetnukeapps

Any help would be greatly appreciated!!!

(History is that I was working then went off to do something else, apparantly got logged out, and now I can't get the login window to open. It looks like the login link has been reset to the home page! I definitely didn't reset that--at least on purpose. Does it get better after the initial install/config? I keep running into issue after issue before I can get down to developing my sites...)