It happens to best of us: You have an local installation of your favourite CMS - and then you can't remember the password! Login throtteling kicks in, you still can't remember it. And this being a local XAMPP installation, you can't send an email to recover the password.

Here is Ryan¹ to the resuce:

You can always reset your password just by pasting this temporarily into any one of your templates, and then viewing a page that uses the template:

$u = $users->get('admin'); // or whatever your username is
$u->of(false); 
$u->pass = 'your-new-password';
$u->save();

¹ Who is Ryan? Ryan Cramer is the founder and lead developer of ProcessWire.