12Calzetta is quite right.
When you enter your password, you will not see the normal *****. Instead you will see nothing. However, the system is recording your keystrokes and if you have entered your password correctly, you will be able to log on.
When you enter a keystroke if you watch carefully, you may be able to see it briefly and then it will disappear. So what you have to do is very carefully enter your password. If it doesn't work, backspace several times to be sure that there's nothing left in the password box because if you have a character left over from the last failed attempt, then your password will be wrong.
I suggest clicking the 'remember' box once you're successful so you don't have to go through this agony every time you want to log on.
But this is normal, at least it's the way mine is and others I have spoken to. Just remember, the software is recording your keystrokes, so you will be able to log on even though you're not going to see the 'normal' box when you enter your password.