Cannot recreate new password for digital signature

I am using Adobe Acrobat X. I created a digital signature before and forgot the password.  After some searching, I used the method of
removing *.PFX file.  However, when I started to recreate a new digital ID, it still asked me for the old password.  It didn’t ask for the new password at
all.  I don’t know what to do at this stage.  Any suggestions.  Thank you.