diff --git a/vnrhook/include/defs.h b/vnrhook/include/defs.h
index 0c2d7e9..e848366 100644
--- a/vnrhook/include/defs.h
+++ b/vnrhook/include/defs.h
@@ -14,7 +14,6 @@
 //#define ITH_ENGINE_UX_DLL   L"vnrengux.dll"
 
 #define ITH_DLL     L"vnrhook.dll"
-#define ITH_DLL_XP  L"vnrhookxp.dll"
 
 // Pipes
 
@@ -27,24 +26,7 @@
 
 // Mutex
 
-// jichi 7/12/2015:
-// ITH IO name prefix, needed by Windows 10 for NT event and mutex APIs
-// Otherwise, NT functions will return status = STATUS_OBJECT_PATH_SYNTAX_BAD
-//#define ITH_PATH_           L"\\BaseNamedObjects\\"
-#define ITH_PATH_           L""
-
-#define ITH_PROCESS_MUTEX_      ITH_PATH_ L"VNR_PROCESS_" // ITH_%d
 #define ITH_HOOKMAN_MUTEX_      ITH_PATH_ L"VNR_HOOKMAN_" // ITH_HOOKMAN_%d
-#define ITH_DETACH_MUTEX_       ITH_PATH_ L"VNR_DETACH_"  // ITH_DETACH_%d
-
 #define ITH_GRANTPIPE_MUTEX     ITH_PATH_ L"VNR_GRANT_PIPE" // ITH_GRANT_PIPE
 
-#define ITH_CLIENT_MUTEX        ITH_PATH_ L"VNR_CLIENT"   // ITH_DLL_RUNNING
-#define ITH_SERVER_MUTEX        ITH_PATH_ L"VNR_SERVER"   // ITH_RUNNING
-#define ITH_SERVER_HOOK_MUTEX   ITH_PATH_ L"VNR_SERVER_HOOK"    // original
-
-// Events
-
-#define ITH_REMOVEHOOK_EVENT    ITH_PATH_ L"VNR_REMOVE_HOOK"  // ITH_REMOVE_HOOK
-
 // EOF
diff --git a/vnrhook/src/main.cc b/vnrhook/src/main.cc
index 57a7290..c6fb780 100644
--- a/vnrhook/src/main.cc
+++ b/vnrhook/src/main.cc
@@ -94,14 +94,8 @@ BOOL WINAPI DllMain(HINSTANCE hModule, DWORD fdwReason, LPVOID unused)
         wchar_t hm_mutex[0x100];
         swprintf(hm_mutex, ITH_HOOKMAN_MUTEX_ L"%d", GetCurrentProcessId());
 		::hmMutex = CreateMutexW(nullptr, FALSE, hm_mutex);
-      }
-      {
-        wchar_t dll_mutex[0x100];
-        swprintf(dll_mutex, ITH_PROCESS_MUTEX_ L"%d", GetCurrentProcessId());
-        DWORD exists;
-		::hMutex = CreateMutexW(nullptr, TRUE, dll_mutex); // jichi 9/18/2013: own is true, make sure the injected dll is singleton
-        if (GetLastError() == ERROR_ALREADY_EXISTS)
-          return FALSE;
+		if (GetLastError() == ERROR_ALREADY_EXISTS)
+			return FALSE;
       }
 
       ::running = true;