setlang.exe is a process belonging to the Microsoft Office family of products, and allows you to configure language and regional settings options for your documents. "This program is a non-essential process, but should not be terminated unless suspected to be causing problems. "
Non-system processes like setlang.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