1. If Welcome screen is turned on.
Open the Control Panel > User Accounts. Click Change the way users log on or off. Check the box Use the Welcome screen. Click Apply Options.
2. Guest account access must be turned off.
Open the Control Panel >User Accounts. Unless the Guest account says that it is already turned off, click the icon for the Guest account, and click Turn off the Guest access.
3. There must be only one user account on the computer.
If you have more than one account (not counting the now disabled Guest account), you have to delete all but one.
Logged in as an administrator, open Windows Explorer and browse to the C:\Documents and Settings folder. In turn, click on the subfolder for each account you are about to delete and harvest anything you want to keep from its subfolders, moving them to another location. When finished with this, close Windows Explorer.
Then, open the Control Panel > User Accounts. Click the icon for the account you want to delete. Click Delete the account.
4. The user account must not have a password.
Open the Control Panel > User Accounts. There should be only the one account you want to keep, plus a disabled Guest account. Click the icon for the account you will be using. If the option is available on the menu to the left, click Remove my password. When prompted, provide the current password as a confirmation.