What are the involved processes in Windows 7 login authentication and what do they do?
Like the most secure logins, Windows uses an hash function to check if the password is correct. When you set the first time your password, it was saved in an hash format. Every time you login into Windows, your input password will be hashed and then it will be compared with the hash saved the first time you choosed your password. If the two hashes are equal, then the password is correct.
EDIT: First of all, Windows locate the SAM file at C:/Windows/System32/config, reads it and searches the row corresponding to the user who wants to login. Then hash the input password and save it into a variable. Then compare the value of this variable with the hash string of the SAM file. Are the two hashes egual? Ok, you can login.