I have had the same problem. That is cannot log into the admin or host accounts using default passwords supplied by a clean install using DotNetNuke_4.4.1_Install. I ensured that I had the setup correct via DotNetNuke_4.4.1_Install\Documentation\StarterKit\Welcome.html. I checked the forum and revised things such as the cookies, doing a new browser, permissions etc.

I installed the new version as I had to code a prior version of DNN to overcome some bugs I found, and was excited about the number of bug fixes that version 4.4.1 has.

I am running a prior version of DNN on the same IIS and SQL Server with no problems.

This is what I have done as some sort of fix, I registered a new operator called 1 with a simple password. I was ABLE TO LOGIN. I updated the Users table for the associated operator to state IsSuperUser = -1. I added a UserRoles record for the associated user to included Role 0 (Admin). I am able to be a "host" using this account.

Note that simply copying and pasting aspnet_Membership Password and PasswordSalt does not work - i.e. I tried to copy the new registered operators password into the host and admin accounts - it kind of worked then didn't. Too strange to bother about.

I have no doubt that I may have created more problems than fixed - but at least I can start doing the content for the web pages.

Hope this helps you.