I'm developing a desktop application in C#. In my application user should login before using my application. Now I want to save my username and password securely.
I know about hashing my username\password and adding salt to my password and saving hashed data in a file; but in this case user can replace this file with previous one. And I know we can't prevent this completely but I want make it hard.
One solution is storing hash of file in registry to prevent changing this file; but I think there should be a better solution.
Edit: I don't use database and I'm using windows 7.