diff --git a/widget/windows/nsIMM32Handler.cpp b/widget/windows/nsIMM32Handler.cpp
index 2c4f0be6a6b4..a50e6d7c67bc 100644
--- a/widget/windows/nsIMM32Handler.cpp
+++ b/widget/windows/nsIMM32Handler.cpp
@@ -41,7 +41,6 @@ static UINT sWM_MSIME_MOUSE = 0; // mouse message for MSIME 98/2000
 #define IMEMOUSE_WUP        0x10    // wheel up
 #define IMEMOUSE_WDOWN      0x20    // wheel down
 
-bool nsIMM32Handler::sIsStatusChanged = false;
 bool nsIMM32Handler::sIsIME = true;
 bool nsIMM32Handler::sIsIMEOpening = false;
 
@@ -704,29 +703,6 @@ nsIMM32Handler::OnIMENotify(nsWindow* aWindow,
   }
 #endif // PR_LOGGING
 
-  if (::GetKeyState(NS_VK_ALT) >= 0) {
-    return false;
-  }
-
-  // XXXmnakano Following code was added by bug 28852 (Key combo to trun ON/OFF
-  // Japanese IME incorrectly activates "File" menu).  If one or more keypress
-  // events come between Alt keydown event and Alt keyup event, XUL menubar
-  // isn't activated by the Alt keyup event.  Therefore, this code sends dummy
-  // keypress event to Gecko.  But this is ugly, and this fires incorrect DOM
-  // keypress event.  So, we should find another way for the bug.
-
-  // add hacky code here
-  mozilla::widget::ModifierKeyState modKeyState(false, false, true);
-  mozilla::widget::NativeKey nativeKey; // Dummy is okay for this usage.
-  nsKeyEvent keyEvent(true, NS_KEY_PRESS, aWindow);
-  keyEvent.keyCode = 192;
-  aWindow->InitKeyEvent(keyEvent, nativeKey, modKeyState);
-  aWindow->DispatchKeyEvent(keyEvent, nullptr);
-  sIsStatusChanged = sIsStatusChanged || (wParam == IMN_SETOPENSTATUS);
-  PR_LOG(gIMM32Log, PR_LOG_ALWAYS,
-    ("IMM32: OnIMENotify, sIsStatusChanged=%s\n",
-     sIsStatusChanged ? "TRUE" : "FALSE"));
-
   // not implement yet
   return false;
 }
diff --git a/widget/windows/nsIMM32Handler.h b/widget/windows/nsIMM32Handler.h
index 0bd5f75d01ae..fb6f53d05f38 100644
--- a/widget/windows/nsIMM32Handler.h
+++ b/widget/windows/nsIMM32Handler.h
@@ -82,12 +82,9 @@ public:
   {
     return IsComposing() && IsComposingWindow(aWindow);
   }
-  static bool IsStatusChanged() { return sIsStatusChanged; }
 
   static bool IsDoingKakuteiUndo(HWND aWnd);
 
-  static void NotifyEndStatusChange() { sIsStatusChanged = false; }
-
   static bool CanOptimizeKeyAndIMEMessages(MSG *aNextKeyOrIMEMessage);
 
 #ifdef DEBUG
@@ -292,7 +289,6 @@ protected:
   bool mIsComposingOnPlugin;
   bool mNativeCaretIsCreated;
 
-  static bool sIsStatusChanged;
   static bool sIsIME;
   static bool sIsIMEOpening;
 
diff --git a/widget/windows/nsWindow.cpp b/widget/windows/nsWindow.cpp
index 82c767b11833..912c51b0d21c 100644
--- a/widget/windows/nsWindow.cpp
+++ b/widget/windows/nsWindow.cpp
@@ -5707,12 +5707,7 @@ LRESULT nsWindow::ProcessKeyUpMessage(const MSG &aMsg, bool *aEventDispatched)
     return FALSE;
   }
 
-  if (!nsIMM32Handler::IsComposingOn(this) &&
-      (aMsg.message != WM_KEYUP || aMsg.wParam != VK_MENU)) {
-    // Ignore VK_MENU if it's not a system key release, so that the menu bar does not trigger
-    // This helps avoid triggering the menu bar for ALT key accelerators used in
-    // assistive technologies such as Window-Eyes and ZoomText, and when using Alt+Tab
-    // to switch back to Mozilla in Windows 95 and Windows 98
+  if (!nsIMM32Handler::IsComposingOn(this)) {
     return OnKeyUp(aMsg, modKeyState, aEventDispatched);
   }
 
@@ -5751,9 +5746,7 @@ LRESULT nsWindow::ProcessKeyDownMessage(const MSG &aMsg,
     return FALSE;
 
   LRESULT result = 0;
-  if (modKeyState.IsAlt() && nsIMM32Handler::IsStatusChanged()) {
-    nsIMM32Handler::NotifyEndStatusChange();
-  } else if (!nsIMM32Handler::IsComposingOn(this)) {
+  if (!nsIMM32Handler::IsComposingOn(this)) {
     result = OnKeyDown(aMsg, modKeyState, aEventDispatched, nullptr);
     // OnKeyDown cleaned up the redirected message information itself, so,
     // we should do nothing.
@@ -6863,6 +6856,13 @@ LRESULT nsWindow::OnKeyUp(const MSG &aMsg,
   NativeKey nativeKey(gKbdLayout, this, aMsg);
   keyupEvent.keyCode = nativeKey.GetDOMKeyCode();
   InitKeyEvent(keyupEvent, nativeKey, aModKeyState);
+  // Set defaultPrevented of the key event if the VK_MENU is not a system key
+  // release, so that the menu bar does not trigger.  This helps avoid
+  // triggering the menu bar for ALT key accelerators used in assistive
+  // technologies such as Window-Eyes and ZoomText or for switching open state
+  // of IME.
+  keyupEvent.mFlags.mDefaultPrevented =
+    (aMsg.wParam == VK_MENU && aMsg.message != WM_SYSKEYUP);
   return DispatchKeyEvent(keyupEvent, &aMsg);
 }