MacBook Pro :: Not Recognizing User Login Password?

After installing new hard drive and transferring time machine data, my MacBook Pro is Refusing to recognise my password even after I have reset it using the startup disk. I enter user password on my admin user account and it goes blue briefly as if beginning load but the. Returns back to selecting user and entering password. It really strange as it does not say password incorrect its almost like it trying to load but can't.