This is a quick information that allows your computer to logon automatically at the startup of Windows Vista (Also Works in Windows 7). You can select and set the user account that will be use during the startup.
Login Automatically in Windows Vista
<<-Advanced User Accounts Control Panel->>
Open the RUN window (Press Windows+R)->type "netplwiz" and press Enter. Select "Continue" if the UAC pop-ups.
In the Advanced User Account window, uncheck the checkbox "User must enter a username and password to use this computer.", then click the "Apply" button. Once the Automatic Log On Window appears, set the username and password that will be use during the startup of Windows Vista.
For Windows XP or manually setting in the registry, Read here.
Simple but sometimes useful… It removes your annoyances. Enjoy!