Is there a specific location where the passwords are stored ?
Are they salted ?
Normally this is
c:\windows\system32\config\SAM The passwords can be either LANMAN or NTLM. LANMAN does not use a salt and is extremely weak. On Windows XP and earlier LANMAN hashes are enabled by default. These do not use salting and are extremely easy to crack or lookup in a rainbow table. They should be disabled so the system uses NTLM hashes (which are salted). As of Windows Vista NTLM is enabled by default.