Retrieving a user's password for verification
What I would correct in the code:


if anything goes wrong it's best to just display "Login incorrect", instead of specialized messages ('user not found' / 'incorrect passsword'). Giving too many details may lead to information leakage
searchUser is not a very good variable name. It in fact represents the result of a search, so I'd name it matchedUser. searchUser would be a good name for a query.
the encryptedPassword variable is assigned but never used. You could use it to compare against the password hash in the database


In the end, my code would look like this:

private void userVerification()
{
    var myDbContext = new DataClasses1DataContext(dbPath);

    var hasher = new Hasher { SaltSize = 16 };
    var encryptedPassword = hasher.Encrypt(txtPassword.Text);

    var matchedUser = myDbContext.Accounts
        .Where( user =&gt;
                user.accnt_User == txtUser.Text &amp;&amp;
                user.accnt_Pass == encryptedPassword)
        .FirstOrDefault();

    if(matchedUser != null)
        MessageBox.Show("CORRECT!");
    else
        MessageBox.Show("Invalid user or password.");
}