SQL Password is a password recovery tool for MS SQL Server 2000, 2005, 2005 Express and MSDE 2000 (Microsoft SQL Server Desktop Engine).
You can either try to find the original password (this may take a lot of time) or reset the password to a known one.
For further info , see http://lastbit.com/sqlpassword/
To set new password :
sp_password @new = 'newpassword', @loginame = 'loginname'