Can't log into Windows XP

My Windows XP laptop won't allow me to log in and claims my password has expired and needs to be reset. Problem is I don't know of any password - previously when I booted the system it went all the way to the desktop without requesting a password.

 

As this seems to be the only account on the computer (e.g. the administrator account?), I restarted in safe mode and got to some 'lost password wizard, which ironically asked for my current password.

 

Is there anything I can do - any help is much appreciated!

 

Martin