Step 1: Click start and select run / or you may type into the search box:
regedit
Step 2: Next you will want to navigate to:
HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Winlogon
Step 3: Now add these values or change the following:
Name : AutoAdminLogon Value : 1
Name : DefaultPassword Value : the pasword of the user profile (If this does not exist use the right-click button and add the string value it is case sensitive )
Name : DefaultUsername Value : the username of the account you want to log in to (If this does not exist use the right-click button and add the string value it is case sensitive ) "keep in mind that if your on a domain to type the username as: domain\username"