PHP Warning: require_once

PS C:\Users\HP\pizzahouse> php artisan serve
PHP Warning: require_once(C:\Users\HP\pizzahouse/bootstrap/app.php):
failed to open stream: No such file or directory in C:\Users\HP\pizzahouse\artisan on line 20
PHP Fatal error: require_once(): Failed opening required 'C:\Users\HP\pizzahouse/bootstrap/app.php' (include_path='.;C:\php\pear') in C:\Users\HP\pizzahouse\artisan on line 20