dot1xcfg.exe is part of Intel PRO/Wireless Network Connection Software. This program is important for the wireless network to function. Removing this process or not depends on whether or not you use wireless networking.
Non-system processes like dot1xcfg.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