Thanks for the info. I agree with the comments about Nir Sofer's tools although I have to carry them on a usb stick with write protection as any good av program detects several of them as dangerous, which they are of course if not used for support.
One free windows password recovery utility I've used successfully in the past, when the user had forgotten their admin login and naturally no password reset disk, is 'Offline Password & Registry Editor' (http://pogostick.net/~pnh/ntpasswd/) - Free boot disk or usb key.
****Please note that this one removes the password so if there are any encrypted (EFS) files they will be inaccessible after resetting the password*** - I wonder if the password reset tools above can deal with efs?