Lock+your+Windows+7+computer+with+a+USB+key

The Security Accounts Manager (SAM) database is where your user password hash values are stored in encrypted form. For better security, you can store the SAM database on a USB key so you can take it out and take it with you. You can even set a password that will have to be entered to decrypt the system key to access the SAM database. All of this is done using the Syskey utility. Here are the instructions for [|using Syskey to protect the SAM database].
 * Lock your Windows 7 computer with a USB key**