You have a computer running Windows 7 or Windows 8.
The computer has a fingerprint reader.
You have configured the fingerprint reader for Single Sign-on. This feature allows you to scan your fingerprint early in the boot process and pass that authentication information to Windows once Windows starts. With Single Sign-on enabled you do not need to provide a username and password to logon to Windows if you have provided your fingerprint during boot.
You have disabled the fast startup option of the Shutdown settings within Power Options Control Panel.
In the scenario above, Windows may require you to enter your username and password rather than using the previously provided fingerprint-based authentication information.
The problem occurs because of a timing issue between the Windows logon process and the fingerprint reader driver.
To workaround this issue, either:
Enable the fast startup option of the Shutdown settings in the Power Options Control Panel.
Provide a username and password when prompted by Windows