hey if you just want to bypass it not get rid of it you can use konboot. if you get hirens boot disk avalible here
http://www.hirensbootcd.org/files/Hirens.BootCD.14.0.zip. then you can burn that to a cd using a program like cdburnerxp (yes it works with vist/7) then you restart your computer with the cd in the drive and you boot off the cd when hirens boot cd loads you will see a black screen with a bunch of options use the arrow keys to select the one you want go down the list and you will find kon-boot click enter when you have it selected and then when the kon-boot screen loads press enter again give it a couple min and your computer will start, then just click on the account you want to logon to and magic it logs on with no password. if you want to wipe the password just let me know and i will help you