Last week, I did a wrong thing: Move a XP(VM) out of the domain but forgot to write down the local administrator's password.  I could not login to that virtual machine later on. What can I do with it? Reinstallation is not so hard by re-imaging, but it waste time.
Later, I found this website: http://www.petri.co.il/forgot_administrator_password.htm give the list of the freeware of password recovery. I decided to try it.
I chose " Petter Nordahl-Hagen's Offline NT Password & Registry Editor" because this one could be used on Vista. Finally I get to access the system by this tool. The following recorded what happened when running the tool.

1. Download the software ( bootable p_w_picpath)
2. Setup the 2003VM's CDROM using the .iso file
3. Make the 2003vm boot from CDROM
4. Choose the options,
5. Check the status of Administrator's status

6. Change back the boot sequency start from Harddisk

Everything is OK now! Thanks for the great freeware!