Log in to XP

I have a Dell latitude laptop without an internal floppy drive. I have set the security on my laptop to be too secure. Now I can't log on to my laptop. I need to bypass the logon screen to get to DOS. HOW CAN i DO THIS WITHOUT GETTING THAT STUPID WELCOME SCREEN? which prevents me from going any further unless I supply the correct password for both the accounts I have setup. The password that I use is the correct one however XP does not recognize them and displays that error message "Did you forget your password" No I didn't because I used the same one for both accounts.