avcenter.exe is a process belonging to Avira Internet Security Suite which protects your computer against Internet-bound threats such as spyware and trojans which can be distributed through e-mail or attack directly to the computer allowing unauthorized access to your computer.
This program is important for the stable and secure running of your computer and should not be terminated.
Non-system processes like avcenter.exe originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that over time your registry suffers fragmentation and accumulates invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues