Now that Windows 7 has been launched, it’s likely that many people will be changing to that operating system or buying new machines with it installed.
Many desktop computers will be used by single users, couples or families who do not wish to have separate profiles and who would prefer not to have to enter a password every time they start their computer.

Achieving this seems not to be very well documented. So, for those wishing to remove the start up password, Click 'Start', open the Control Panel and click on User Accounts. Find ‘Remove password’ (Right-hand column, in Blue) and click on that, you will have to enter the current password before Windows will allow you to delete it.
Make sure that there are no other named accounts and that the Guest account is selected to off.

Next time you start your machine, Windows will just start without the need to enter a password. For fairly obvious reasons this is not a good idea for laptops or notebooks.

LorryOil