diff --git a/Core/Core.cpp b/Core/Core.cpp
index 95864b197a..af371a29b6 100644
--- a/Core/Core.cpp
+++ b/Core/Core.cpp
@@ -308,8 +308,8 @@ void Core_ProcessStepping() {
 	static int lastSteppingCounter = -1;
 	if (lastSteppingCounter != steppingCounter) {
 		CBreakPoints::ClearTemporaryBreakPoints();
-		host->UpdateDisassembly();
-		host->UpdateMemView();
+		System_Notify(SystemNotification::DISASSEMBLY);
+		System_Notify(SystemNotification::MEM_VIEW);
 		lastSteppingCounter = steppingCounter;
 	}
 
@@ -320,15 +320,15 @@ void Core_ProcessStepping() {
 	if (doStep && coreState == CORE_STEPPING) {
 		Core_SingleStep();
 		// Update disasm dialog.
-		host->UpdateDisassembly();
-		host->UpdateMemView();
+		System_Notify(SystemNotification::DISASSEMBLY);
+		System_Notify(SystemNotification::MEM_VIEW);
 	}
 }
 
 // Many platforms, like Android, do not call this function but handle things on their own.
 // Instead they simply call NativeRender and NativeUpdate directly.
 bool Core_Run(GraphicsContext *ctx) {
-	host->UpdateDisassembly();
+	System_Notify(SystemNotification::DISASSEMBLY);
 	while (true) {
 		if (GetUIState() != UISTATE_INGAME) {
 			Core_StateProcessed();
diff --git a/Core/Debugger/Breakpoints.cpp b/Core/Debugger/Breakpoints.cpp
index 5ce977ec45..cd3df9bf99 100644
--- a/Core/Debugger/Breakpoints.cpp
+++ b/Core/Debugger/Breakpoints.cpp
@@ -19,6 +19,7 @@
 #include <atomic>
 #include <mutex>
 
+#include "Common/System/System.h"
 #include "Common/Log.h"
 #include "Core/Core.h"
 #include "Core/Debugger/Breakpoints.h"
@@ -674,7 +675,7 @@ void CBreakPoints::Update(u32 addr) {
 	}
 
 	// Redraw in order to show the breakpoint.
-	host->UpdateDisassembly();
+	System_Notify(SystemNotification::DISASSEMBLY);
 }
 
 bool CBreakPoints::ValidateLogFormat(DebugInterface *cpu, const std::string &fmt) {
diff --git a/Core/Debugger/WebSocket/GameSubscriber.cpp b/Core/Debugger/WebSocket/GameSubscriber.cpp
index efa8ff2da6..4ca0f3e5cb 100644
--- a/Core/Debugger/WebSocket/GameSubscriber.cpp
+++ b/Core/Debugger/WebSocket/GameSubscriber.cpp
@@ -55,8 +55,9 @@ void WebSocketGameReset(DebuggerRequest &req) {
 		ERROR_LOG(BOOT, "Error resetting: %s", resetError.c_str());
 		return req.Fail("Could not reset");
 	}
+
 	System_Notify(SystemNotification::BOOT_DONE);
-	host->UpdateDisassembly();
+	System_Notify(SystemNotification::DISASSEMBLY);
 
 	req.Respond();
 }
diff --git a/Core/HLE/sceUmd.cpp b/Core/HLE/sceUmd.cpp
index 8ad8a5196a..c7591f13d7 100644
--- a/Core/HLE/sceUmd.cpp
+++ b/Core/HLE/sceUmd.cpp
@@ -17,6 +17,7 @@
 
 #include <vector>
 
+#include "Common/System/System.h"
 #include "Common/Serialize/Serializer.h"
 #include "Common/Serialize/SerializeFuncs.h"
 #include "Common/Serialize/SerializeMap.h"
@@ -104,8 +105,9 @@ void __UmdDoState(PointerWrap &p)
 
 	if (s > 1) {
 		Do(p, UMDReplacePermit);
-		if (UMDReplacePermit)
-			host->UpdateUI();
+		if (UMDReplacePermit) {
+			System_Notify(SystemNotification::UI);
+		}
 	}
 	if (s > 2) {
 		Do(p, umdInsertChangeEvent);
diff --git a/Core/Host.h b/Core/Host.h
index ff5179b3e2..5fc61c220e 100644
--- a/Core/Host.h
+++ b/Core/Host.h
@@ -27,9 +27,6 @@ class Host {
 public:
 	virtual ~Host() {}
 
-	virtual void UpdateUI() {}
-	virtual void UpdateMemView() {}
-	virtual void UpdateDisassembly() {}
 	virtual void NotifySymbolMapUpdated() {}
 	virtual void SetDebugMode(bool mode) { }
 	virtual void NotifySwitchUMDUpdated() {}
diff --git a/Core/SaveState.cpp b/Core/SaveState.cpp
index c35d1c9230..6386ca09ee 100644
--- a/Core/SaveState.cpp
+++ b/Core/SaveState.cpp
@@ -1080,7 +1080,7 @@ namespace SaveState
 				return;
 			}
 			System_Notify(SystemNotification::BOOT_DONE);
-			host->UpdateDisassembly();
+			System_Notify(SystemNotification::DISASSEMBLY);
 			needsRestart = false;
 		}
 	}
diff --git a/Core/System.cpp b/Core/System.cpp
index 8303f08a15..4f6510f07e 100644
--- a/Core/System.cpp
+++ b/Core/System.cpp
@@ -124,8 +124,7 @@ void UpdateUIState(GlobalUIState newState) {
 	// Never leave the EXIT state.
 	if (globalUIState != newState && globalUIState != UISTATE_EXIT) {
 		globalUIState = newState;
-		if (host)
-			host->UpdateDisassembly();
+		System_Notify(SystemNotification::DISASSEMBLY);
 		const char *state = nullptr;
 		switch (globalUIState) {
 		case UISTATE_EXIT: state = "exit";  break;
diff --git a/Qt/QtHost.h b/Qt/QtHost.h
index f559265494..a9816f7be4 100644
--- a/Qt/QtHost.h
+++ b/Qt/QtHost.h
@@ -30,16 +30,6 @@ public:
 		mainWindow = mainWindow_;
 	}
 
-	void UpdateUI() override {
-		mainWindow->updateMenus();
-	}
-
-	void UpdateMemView() override {
-	}
-	void UpdateDisassembly() override {
-		mainWindow->updateMenus();
-	}
-
 	void SetDebugMode(bool mode) override {}
 
 	bool InitGraphics(std::string *error_message, GraphicsContext **ctx) override { return true; }
diff --git a/UI/EmuScreen.cpp b/UI/EmuScreen.cpp
index 09ee8b2629..e5c03ba69b 100644
--- a/UI/EmuScreen.cpp
+++ b/UI/EmuScreen.cpp
@@ -355,8 +355,7 @@ void EmuScreen::bootGame(const Path &filename) {
 void EmuScreen::bootComplete() {
 	UpdateUIState(UISTATE_INGAME);
 	System_Notify(SystemNotification::BOOT_DONE);
-
-	host->UpdateDisassembly();
+	System_Notify(SystemNotification::DISASSEMBLY);
 
 	NOTICE_LOG(BOOT, "Loading %s...", PSP_CoreParameter().fileToStart.c_str());
 	autoLoad();
@@ -448,7 +447,7 @@ static void AfterSaveStateAction(SaveState::Status status, const std::string &me
 static void AfterStateBoot(SaveState::Status status, const std::string &message, void *ignored) {
 	AfterSaveStateAction(status, message, ignored);
 	Core_EnableStepping(false);
-	host->UpdateDisassembly();
+	System_Notify(SystemNotification::DISASSEMBLY);
 }
 
 void EmuScreen::sendMessage(const char *message, const char *value) {
@@ -461,12 +460,12 @@ void EmuScreen::sendMessage(const char *message, const char *value) {
 		bootPending_ = false;
 		stopRender_ = true;
 		invalid_ = true;
-		host->UpdateDisassembly();
+		System_Notify(SystemNotification::DISASSEMBLY);
 	} else if (!strcmp(message, "reset")) {
 		PSP_Shutdown();
 		bootPending_ = true;
 		invalid_ = true;
-		host->UpdateDisassembly();
+		System_Notify(SystemNotification::DISASSEMBLY);
 
 		std::string resetError;
 		if (!PSP_InitStart(PSP_CoreParameter(), &resetError)) {
diff --git a/UI/GameSettingsScreen.cpp b/UI/GameSettingsScreen.cpp
index b368e8114f..6556a57193 100644
--- a/UI/GameSettingsScreen.cpp
+++ b/UI/GameSettingsScreen.cpp
@@ -913,8 +913,7 @@ void GameSettingsScreen::CreateSystemSettings(UI::ViewGroup *systemSettings) {
 		auto langScreen = new NewLanguageScreen(sy->T("Language"));
 		langScreen->OnChoice.Add([&](UI::EventParams &e) {
 			screenManager()->RecreateAllViews();
-			if (host)
-				host->UpdateUI();
+			System_Notify(SystemNotification::UI);
 			return UI::EVENT_DONE;
 		});
 		if (e.v)
@@ -1362,7 +1361,7 @@ void GameSettingsScreen::onFinish(DialogResult result) {
 		g_Config.unloadGameConfig();
 	}
 
-	host->UpdateUI();
+	System_Notify(SystemNotification::UI);
 
 	KeyMap::UpdateNativeMenuKeys();
 
@@ -1895,7 +1894,7 @@ void GameSettingsScreen::CallbackRestoreDefaults(bool yes) {
 	if (yes) {
 		g_Config.RestoreDefaults(RestoreSettingsBits::SETTINGS);
 	}
-	host->UpdateUI();
+	System_Notify(SystemNotification::UI);
 }
 
 UI::EventReturn GameSettingsScreen::OnRestoreDefaultSettings(UI::EventParams &e) {
diff --git a/UI/HostTypes.h b/UI/HostTypes.h
index 2cdc0a9d84..de5b35fdee 100644
--- a/UI/HostTypes.h
+++ b/UI/HostTypes.h
@@ -24,11 +24,6 @@ class NativeHost : public Host {
 public:
 	NativeHost() {}
 
-	void UpdateUI() override {}
-
-	void UpdateMemView() override {}
-	void UpdateDisassembly() override {}
-
 	void SetDebugMode(bool mode) override { }
 
 	bool InitGraphics(std::string *error_message, GraphicsContext **ctx) override { return true; }
diff --git a/UI/MainScreen.cpp b/UI/MainScreen.cpp
index ba2b3e9276..682fe85074 100644
--- a/UI/MainScreen.cpp
+++ b/UI/MainScreen.cpp
@@ -964,9 +964,7 @@ UI::EventReturn GameBrowser::GridSettingsClick(UI::EventParams &e) {
 
 UI::EventReturn GameBrowser::OnRecentClear(UI::EventParams &e) {
 	screenManager_->RecreateAllViews();
-	if (host) {
-		host->UpdateUI();
-	}
+	System_Notify(SystemNotification::UI);
 	return UI::EVENT_DONE;
 }
 
diff --git a/UI/MiscScreens.cpp b/UI/MiscScreens.cpp
index 170844f6a4..c99684bbe0 100644
--- a/UI/MiscScreens.cpp
+++ b/UI/MiscScreens.cpp
@@ -431,9 +431,7 @@ void HandleCommonMessages(const char *message, const char *value, ScreenManager
 		auto langScreen = new NewLanguageScreen(sy->T("Language"));
 		langScreen->OnChoice.Add([](UI::EventParams &) {
 			NativeMessageReceived("recreateviews", "");
-			if (host) {
-				host->UpdateUI();
-			}
+			System_Notify(SystemNotification::UI);
 			return UI::EVENT_DONE;
 		});
 		manager->push(langScreen);
diff --git a/UWP/PPSSPP_UWPMain.cpp b/UWP/PPSSPP_UWPMain.cpp
index a1630b9166..1529a18887 100644
--- a/UWP/PPSSPP_UWPMain.cpp
+++ b/UWP/PPSSPP_UWPMain.cpp
@@ -438,13 +438,6 @@ bool System_GetPropertyBool(SystemProperty prop) {
 
 void System_Notify(SystemNotification notification) {
 	switch (notification) {
-	case SystemNotification::BOOT_DONE:
-		g_symbolMap->SortSymbols();
-
-		SetDebugMode(false);
-		Core_EnableStepping(false);
-		break;
-
 	default:
 		break;
 	}
diff --git a/UWP/UWPHost.cpp b/UWP/UWPHost.cpp
index f8ddcfc22d..58c30f704d 100644
--- a/UWP/UWPHost.cpp
+++ b/UWP/UWPHost.cpp
@@ -64,7 +64,6 @@ void UWPHost::ShutdownGraphics() {
 }
 
 void UWPHost::SetWindowTitle(const char *message) {
-	// Should really be done differently
 }
 
 void UWPHost::InitSound() {
@@ -76,15 +75,6 @@ void UWPHost::UpdateSound() {
 void UWPHost::ShutdownSound() {
 }
 
-void UWPHost::UpdateUI() {
-}
-
-void UWPHost::UpdateMemView() {
-}
-
-void UWPHost::UpdateDisassembly() {
-}
-
 void UWPHost::SetDebugMode(bool mode) {}
 
 void UWPHost::PollControllers() {
diff --git a/UWP/UWPHost.h b/UWP/UWPHost.h
index 4e604222bb..038bf9becb 100644
--- a/UWP/UWPHost.h
+++ b/UWP/UWPHost.h
@@ -12,9 +12,6 @@ public:
 	UWPHost();
 	~UWPHost();
 
-	void UpdateMemView() override;
-	void UpdateDisassembly() override;
-	void UpdateUI() override;
 	void SetDebugMode(bool mode) override;
 
 	// If returns false, will return a null context
diff --git a/Windows/EmuThread.cpp b/Windows/EmuThread.cpp
index c4225d95d8..5c3798bc7c 100644
--- a/Windows/EmuThread.cpp
+++ b/Windows/EmuThread.cpp
@@ -161,7 +161,7 @@ void MainThreadFunc() {
 		// Let's continue (and probably crash) just so they have a way to keep trying.
 	}
 
-	host->UpdateUI();
+	System_Notify(SystemNotification::UI);
 
 	std::string error_string;
 	bool success = host->InitGraphics(&error_string, &g_graphicsContext);
diff --git a/Windows/WindowsHost.cpp b/Windows/WindowsHost.cpp
index d39c172abe..f270d79c02 100644
--- a/Windows/WindowsHost.cpp
+++ b/Windows/WindowsHost.cpp
@@ -189,26 +189,6 @@ void WindowsHost::UpdateSound() {
 void WindowsHost::ShutdownSound() {
 }
 
-void WindowsHost::UpdateUI() {
-	PostMessage(mainWindow_, MainWindow::WM_USER_UPDATE_UI, 0, 0);
-
-	int peers = GetInstancePeerCount();
-	if (PPSSPP_ID >= 1 && peers != lastNumInstances_) {
-		lastNumInstances_ = peers;
-		PostMessage(mainWindow_, MainWindow::WM_USER_WINDOW_TITLE_CHANGED, 0, 0);
-	}
-}
-
-void WindowsHost::UpdateMemView() {
-	if (memoryWindow)
-		PostDialogMessage(memoryWindow, WM_DEB_UPDATE);
-}
-
-void WindowsHost::UpdateDisassembly() {
-	if (disasmWindow)
-		PostDialogMessage(disasmWindow, WM_DEB_UPDATE);
-}
-
 void WindowsHost::SetDebugMode(bool mode) {
 	if (disasmWindow)
 		PostDialogMessage(disasmWindow, WM_DEB_SETDEBUGLPARAM, 0, (LPARAM)mode);
diff --git a/Windows/WindowsHost.h b/Windows/WindowsHost.h
index 94436f5479..42e7e62094 100644
--- a/Windows/WindowsHost.h
+++ b/Windows/WindowsHost.h
@@ -34,9 +34,6 @@ public:
 		UpdateConsolePosition();
 	}
 
-	void UpdateMemView() override;
-	void UpdateDisassembly() override;
-	void UpdateUI() override;
 	void SetDebugMode(bool mode) override;
 
 	// If returns false, will return a null context
@@ -74,7 +71,6 @@ private:
 	GraphicsContext *gfx_ = nullptr;
 	size_t numDinputDevices_ = 0;
 	std::wstring lastTitle_;
-	int lastNumInstances_ = 0;
 
 	std::list<std::unique_ptr<InputDevice>> input;
 };
diff --git a/Windows/main.cpp b/Windows/main.cpp
index af0f555e8d..b10e10321e 100644
--- a/Windows/main.cpp
+++ b/Windows/main.cpp
@@ -47,6 +47,7 @@
 #include "Core/Config.h"
 #include "Core/ConfigValues.h"
 #include "Core/SaveState.h"
+#include "Core/Instance.h"
 #include "Windows/EmuThread.h"
 #include "Windows/WindowsAudio.h"
 #include "ext/disarm.h"
@@ -110,6 +111,7 @@ int g_activeWindow = 0;
 
 static std::thread inputBoxThread;
 static bool inputBoxRunning = false;
+int g_lastNumInstances = 0;
 
 void System_ShowFileInFolder(const char *path) {
 	// SHParseDisplayName can't handle relative paths, so normalize first.
@@ -377,6 +379,7 @@ static BOOL PostDialogMessage(Dialog *dialog, UINT message, WPARAM wParam = 0, L
 void System_Notify(SystemNotification notification) {
 	switch (notification) {
 	case SystemNotification::BOOT_DONE:
+	{
 		if (g_symbolMap)
 			g_symbolMap->SortSymbols();
 		PostMessage(MainWindow::GetHWND(), WM_USER + 1, 0, 0);
@@ -386,6 +389,29 @@ void System_Notify(SystemNotification notification) {
 			PostDialogMessage(disasmWindow, WM_DEB_SETDEBUGLPARAM, 0, (LPARAM)mode);
 		break;
 	}
+
+	case SystemNotification::UI:
+	{
+		PostMessage(MainWindow::GetHWND(), MainWindow::WM_USER_UPDATE_UI, 0, 0);
+
+		int peers = GetInstancePeerCount();
+		if (PPSSPP_ID >= 1 && peers != g_lastNumInstances) {
+			g_lastNumInstances = peers;
+			PostMessage(MainWindow::GetHWND(), MainWindow::WM_USER_WINDOW_TITLE_CHANGED, 0, 0);
+		}
+		break;
+	}
+
+	case SystemNotification::MEM_VIEW:
+		if (memoryWindow)
+			PostDialogMessage(memoryWindow, WM_DEB_UPDATE);
+		break;
+
+	case SystemNotification::DISASSEMBLY:
+		if (disasmWindow)
+			PostDialogMessage(disasmWindow, WM_DEB_UPDATE);
+		break;
+	}
 }
 
 void System_SendMessage(const char *command, const char *parameter) {
diff --git a/headless/StubHost.h b/headless/StubHost.h
index 585baf4646..d952802e73 100644
--- a/headless/StubHost.h
+++ b/headless/StubHost.h
@@ -26,11 +26,6 @@
 // TODO: Get rid of this junk
 class HeadlessHost : public Host {
 public:
-	void UpdateUI() override {}
-
-	void UpdateMemView() override {}
-	void UpdateDisassembly() override {}
-
 	void SetDebugMode(bool mode) override { }
 
 	void SetGraphicsCore(GPUCore core) { gpuCore_ = core; }