According to Wikipedia,
Biometrics refers to methods for uniquely recognizing humans based upon one or more intrinsic physical or behavioral traits. In information technology, in particular, biometrics is used as a form of identity access management and access control.
The most common biometric device is a fingerprint reader, so I will be using this as the example to show you how to set up and use it in Windows 7.
Setting up the fingerprint reader
I have a fingerprint reader built in my laptop so it shows up in devices and printers without me installing any driver after I installed Windows 7.
Right-click Biometric Coprocessor and choose Biometrics from the context menu, which opens the detail properties window that you can use to set up the device.
Click Manage your fingerprint data in the window to collect or update your fingerprint data, and the Biometric Enrollment window pops up, asking for your login password.
Put in your password, and click OK to get to the next step, the interesting part.
The process of collecting data is quite simple and straightforward. Just click which finger you want to use later on to swipe, and swipe your finger through the reader a few times until Windows thinks it’s good enough. You can store all your fingers if you want to. Click Finish button once you are done.
If your Windows 7 is part of the Windows server domain, you will need to turn on the option “Allow users to log on to a domain using their fingerprints” in Change biometric settings.
And you are all set.
How to use it
It’s also simple enough. When you are in the log in screen, instead typing in username and password, simply swiping your finger which data has been collected earlier across the fingerprint reader. If it is indeed you and you swipe the way it’s supposed to be, you will log in to the system successfully.