lgui64u.dll is a LGui64Dll
belonging to LGui64Dll Dynamic Link Library
from Lingoes Corporation
Non-system processes like lgui64u.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.