Take a look at this. You should be able to use it to browse and possibly change the password.
http://home.eunet.no/~pnordahl/ntpasswd/bootdisk.html
I used this the other day for browsing the registry when a machine wouldn't boot. I could read the values, but when I tried to change them and boot back into Windows, Windows restored a previous version of the registry.
I was however able to get the value data I needed to make the machine bootable again.