jedifurball2,
I had this same issue with a new install, but was able to resolve it. In my case, I have WordPress on a hosted server running IIS. My default settings for IIS prohibit browsing, and my default page was set to default.aspx.
What I did to resolve the issue was to add index.php to the top of my default page listing in IIS. I was then able to login and get properly redirected to the admin page with no further issue. Hope it works for you…
