cant get passed user account

[gologica]

Dont know whats happening here but I botted up the computer today and when I go to my user account it goes to the normal blue screen as if it was loading my desktop then all of a sudden it resets back to the user accounts screen. I dont have to login as I have never had a password I just click on my name and it normally loads up and has done so for the past year or so. I have tried going into admin account but the same thing happens it just reverts back to the accounts screen. I have tried safe mode and that does not work I have tried using the last known working option and that does not work. I cannot get into my account or the admin account. Does anyone have any ideas bearing in mind 'safe mode' and 'last known' dont work either. Any help appreciated