password issue

I have scenario like
I reset my local user password because it was set like "I need to reset when I login for the 1st time".. after I reset it says authentication token updated successfully and closes the session.

after that I login again then it asks me reset it again and again it does not allow to login at all

I do not have any other user ID's to login and check.. also I do not have root user password

Thanks
Arul