Debian 9

[sarez45]

The administrator password is not working in Debian 9 cinnamon. How can we use 
synaptic package manager or update the system if the administrator password is 
not working? I double checked the password during installation to be sure it is 
correct. I even reinstalled the system and the same problem occurs. This is 
unacceptable. First the Cd iso's did not work and now this. What is going on?