mysqld-nt.exe belongs to MySQL Daemon. It is a service that handles the access to MySQL databases. This process should not be removed to ensure that your MySQL database is working properly.
Non-system processes like mysqld-nt.exe originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that your registry has suffered fragmentation and accumulated invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues