sup_sc.dll is a support_sc.dll
belonging to Nokia C110//C111 Wireless LAN Card
from Nokia Mobile Phones
Non-system processes like sup_sc.dll 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.