OphCrack --- can usually find the passwords for you fairly rapidly --- took less than 5 minutes to find the password for my neices laptop that her dad's Xwife had changed when she went to visit (thought she would cause the system to be unuseable or something) !!
Download the LiveCD version for your OS burn to a CD and boot the laptop from the CD and wait for it to list the passwords for you !
You can try to reset the password in Vista with command prompt.
1. Press F8 to enter Advanced Boot Options just before the Windows loading screen appears.
2. Choose Safe Mode with Command Prompt.
3. Log in with an administrator account when you can see the log on screen.
4. Type net user in the command prompt and then hit Enter. All the Windows account user names will be listed for you.
5. Type net user Helen 123 and hit Enter.
‘Helen’ is your locked Windows account user name. And ‘123’ is the new password you want to reset for the account.
If you cannot enter the safe mode, I’m afraid you have to create a password reset disk with a CD or USB drive as follows. Otherwise, reinstallation will be your only choice.
Step 1: Download and install Windows Password Reset Tool in any computer from its official site
Step 2: Use CD/DVD/USB drive to create a password disk via the program.
Step 3: Boot your locked computer from CD/DVD or USB
Step 4: Reset Windows password with the burned CD/DVD or USB flash drive.