If you're the only person using your computer and you've installed Microsoft's .Net Framework upgrade, you can no longer boot into Windows without stopping at the log-in screen. To remove this step, click on the start button and type in 'control userpasswords2' then press Enter. In the 'User Accounts' dialog box, select your own log-in name and uncheck 'Users must enter a user name and password to use this computer' then click 'OK'. In the resulting dialog box, make sure that your log-in name is in the user name field and leave both password fields blank then click 'OK'.