Is there something could let me log on computer without inputting password? Any recommendations? Thanks.
I’ve heard about software that allows you to see the passwords under the “stars” , but what you asked for I do not think it exists. 
Can you rephrase the question; do you mean you have locked yourself out of a Windows computer and want to access the files? For that you could possibly use a Live Linux Distro. to bypass things.
Or do you want to know how to let’s say Install/configure Windows so it doesn’t ask you for a user password after each time you boot up and it loads?
If you’ve locked yourself out, some Windows installations are set up with the administrator account not having a password. Username: administrator Password: [blank]
Otherwise, if you just want to access the files on the hdd a linux live distro could be the way forward.
If you want to log into your Windows computer without having to enter a password, then you need to run the command “Control Userpasswords2”. Full instructions can be found at http://wiki.ljackson.us/Control_Userpasswords2
thank you for all your suggestions. and i want a software which doesn’t ask me for a user password, i do not need to input the username and password.
what about O2FACE?
a friend recently recommend it to me.
You don’t have to use a username and password for Windows Login it has been explained in the replies above; it only asks you to do so if you set-up the OS to ask you for those credentials.
We are assuming it is MS Windows you are using, as you never said.
What I think you really mean; is you would like to use an alternative biometric “secured-method” of logging into password-protected OS Account instead of having to; remember/input passwords via a keyboard, etc.
For example a small PC fingerprint reader.
do you mean
you want to login into computer with out password (which has been assigned some password)
or
you want to remove(dont get) initial password asking dialog box…?