regedit.exe is the executable for the Windows Registry Editor. It is used to view and change the settings in the system registry. This process will only run while you have the editor open and should not be removed.
Non-system processes like regedit.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