Since you have already removed the other user and the passwords for both users, go to Control Panel\Network and change the default Logon to Windows Logon. Then reboot. If the password prompt appears, don't enter anything and just click the OK button. You shouldn't see the prompt again.
2 people used to used the computer, so we activate the password for each person. but now only my self use the computer, so I remove the other user password, but the start up password window still appear, only with my name, but still appear. so I want to turn off the start up password window, but i don't know how. I removed all password in teh computer, so i don't have to type any password in the password window, but i want to remove the password window, if any one know how to do it, please tell me.