3cxfwchecker.dll is a 3CXFWChecker
belonging to 3CX Phone System
from 3CX Software Ltd.
Non-system processes like 3cxfwchecker.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.