Cannot log into new accounts successfully

It might be too late, but you can...
...disconnect from the internet
...uninstall Avira Free Antivirus 2013 (just as a test)
...restart the computer
...try to create a new account/profile.

too late?

the problem came to existence way before I installed Avira. At the time I had MSE

Let's see what other forum members have to say on this issue.