diff --git a/Core/HLE/sceUmd.cpp b/Core/HLE/sceUmd.cpp
index 01a9b5827b..eaf486c223 100644
--- a/Core/HLE/sceUmd.cpp
+++ b/Core/HLE/sceUmd.cpp
@@ -24,6 +24,9 @@
 #include "Core/HLE/sceKernelThread.h"
 #include "Core/HLE/sceKernelInterrupt.h"
 #include "Core/HLE/KernelWaitHelpers.h"
+#include "Core/FileSystems/BlockDevices.h"
+#include "Core/FileSystems/ISOFileSystem.h"
+#include "Core/FileSystems/VirtualDiscFileSystem.h"
 
 const u64 MICRO_DELAY_ACTIVATE = 4000;
 
@@ -36,6 +39,9 @@ static int umdStatChangeEvent = -1;
 static std::vector<SceUID> umdWaitingThreads;
 static std::map<SceUID, u64> umdPausedWaits;
 
+extern IFileSystem* currentUMD;
+bool UMDReplacePermit = false;
+
 struct PspUmdInfo {
 	u32_le size;
 	u32_le type;
@@ -266,7 +272,6 @@ u32 sceUmdRegisterUMDCallBack(u32 cbId)
 		// There's only ever one.
 		driveCBId = cbId;
 	}
-
 	DEBUG_LOG(SCEIO, "%d=sceUmdRegisterUMDCallback(id=%08x)", retVal, cbId);
 	return retVal;
 }
@@ -281,7 +286,6 @@ int sceUmdUnRegisterUMDCallBack(int cbId)
 		retVal = cbId;
 		driveCBId = -1;
 	}
-
 	DEBUG_LOG(SCEIO, "%08x=sceUmdUnRegisterUMDCallBack(id=%08x)", retVal, cbId);
 	return retVal;
 }
@@ -436,14 +440,42 @@ u32 sceUmdGetErrorStat()
 	return umdErrorStat;
 }
 
+void __UmdReplace(std::string filename) {
+	pspFileSystem.Unmount("umd0:", currentUMD);
+	pspFileSystem.Unmount("umd1:", currentUMD);
+	pspFileSystem.Unmount("disc0:", currentUMD);
+	pspFileSystem.Unmount("umd:", currentUMD);
+
+	IFileSystem* umd2;
+	PSPFileInfo info = pspFileSystem.GetFileInfo(filename);
+	if (info.type == FILETYPE_DIRECTORY) {
+		umd2 = new VirtualDiscFileSystem(&pspFileSystem, filename);
+	} else {
+		auto bd = constructBlockDevice(filename.c_str());
+		if (!bd)
+			return;
+		umd2 = new ISOFileSystem(&pspFileSystem, bd);
+		pspFileSystem.Mount("umd0:", umd2);
+		pspFileSystem.Mount("umd1:", umd2);
+		pspFileSystem.Mount("disc0:", umd2);
+		pspFileSystem.Mount("umd:", umd2);
+	}
+	currentUMD = umd2;
+	u32 notifyArg = PSP_UMD_PRESENT | PSP_UMD_READABLE | PSP_UMD_CHANGED;
+	if (driveCBId != -1)
+		__KernelNotifyCallback(driveCBId, notifyArg);
+}
+
 u32 sceUmdReplaceProhibit()
 {
+	UMDReplacePermit = false;
 	DEBUG_LOG(SCEIO,"sceUmdReplaceProhibit()");
 	return 0;
 }
 
 u32 sceUmdReplacePermit()
 {
+	UMDReplacePermit = true;
 	DEBUG_LOG(SCEIO,"sceUmdReplacePermit()");
 	return 0;
 }
diff --git a/Core/HLE/sceUmd.h b/Core/HLE/sceUmd.h
index 3423c88f4c..a4f766eb49 100644
--- a/Core/HLE/sceUmd.h
+++ b/Core/HLE/sceUmd.h
@@ -41,4 +41,6 @@ enum pspUmdType {
 void __UmdInit();
 void __UmdDoState(PointerWrap &p);
 
+void __UmdReplace(std::string filename);
+
 void Register_sceUmdUser();
diff --git a/Core/PSPLoaders.cpp b/Core/PSPLoaders.cpp
index 15a0d86bd3..f69db2b2d3 100644
--- a/Core/PSPLoaders.cpp
+++ b/Core/PSPLoaders.cpp
@@ -42,6 +42,7 @@
 #include "HLE/sceKernelMemory.h"
 #include "ELF/ParamSFO.h"
 
+IFileSystem* currentUMD;
 // We gather the game info before actually loading/booting the ISO
 // to determine if the emulator should enable extra memory and
 // double-sized texture coordinates.
@@ -72,6 +73,8 @@ void InitMemoryForGameISO(std::string fileToStart) {
 	pspFileSystem.Mount("umd1:", umd2);
 	pspFileSystem.Mount("disc0:", umd2);
 	pspFileSystem.Mount("umd:", umd2);
+	currentUMD = umd2;
+
 	std::string gameID;
 
 	std::string sfoPath("disc0:/PSP_GAME/PARAM.SFO");
@@ -205,6 +208,7 @@ bool Load_PSP_ELF_PBP(const char *filename, std::string *error_string)
 			pspFileSystem.Mount("umd1:", umd2);
 			pspFileSystem.Mount("disc0:", umd2);
 			pspFileSystem.Mount("umd:", umd2);
+			currentUMD = umd2;
 		}
 	}
 
diff --git a/UI/MainScreen.cpp b/UI/MainScreen.cpp
index 288c68130e..2dab018b9b 100644
--- a/UI/MainScreen.cpp
+++ b/UI/MainScreen.cpp
@@ -44,6 +44,8 @@
 #include "GPU/GPUInterface.h"
 #include "i18n/i18n.h"
 
+#include "Core/HLE/sceUmd.h"
+
 #ifdef _WIN32
 #include "Windows/W32Util/ShellUtil.h"
 #include "Windows/WndMainWindow.h"
@@ -504,14 +506,14 @@ void MainScreen::CreateViews() {
 	if (vertical) {
 		root_ = new LinearLayout(ORIENT_VERTICAL);
 		rightColumn->ReplaceLayoutParams(new LinearLayoutParams(FILL_PARENT, WRAP_CONTENT));
-		leftColumn->ReplaceLayoutParams(new LinearLayoutParams(1.0));
-		root_->Add(rightColumn);
+		leftColumn->ReplaceLayoutParams(new LinearLayoutParams(1.0));		
+		root_->Add(rightColumn);		
 		root_->Add(leftColumn);
 	} else {
 		root_ = new LinearLayout(ORIENT_HORIZONTAL);
 		leftColumn->ReplaceLayoutParams(new LinearLayoutParams(1.0));
 		rightColumn->ReplaceLayoutParams(new LinearLayoutParams(300, FILL_PARENT, actionMenuMargins));
-		root_->Add(leftColumn);
+		root_->Add(leftColumn);	
 		root_->Add(rightColumn);
 	}
 
@@ -703,6 +705,8 @@ GamePauseScreen::~GamePauseScreen() {
 	}
 }
 
+extern bool UMDReplacePermit;
+
 void GamePauseScreen::CreateViews() {
 	static const int NUM_SAVESLOTS = 5; 
 
@@ -753,6 +757,9 @@ void GamePauseScreen::CreateViews() {
 	rightColumn->Add(rightColumnItems);
 
 	rightColumnItems->SetSpacing(0.0f);
+	if (UMDReplacePermit) {
+		rightColumnItems->Add(new Choice(i->T("Switch UMD")))->OnClick.Handle(this, &GamePauseScreen::OnSwitchUMD);
+	}
 	rightColumnItems->Add(new Choice(i->T("Continue")))->OnClick.Handle<UIScreen>(this, &UIScreen::OnBack);
 	rightColumnItems->Add(new Choice(i->T("Game Settings")))->OnClick.Handle(this, &GamePauseScreen::OnGameSettings);
 	if (g_Config.bEnableCheats) {
@@ -813,6 +820,11 @@ UI::EventReturn GamePauseScreen::OnCwCheat(UI::EventParams &e) {
 	return UI::EVENT_DONE;
 }
 
+UI::EventReturn GamePauseScreen::OnSwitchUMD(UI::EventParams &e) {
+	screenManager()->push(new UmdReplaceScreen());
+	return UI::EVENT_DONE;
+}
+
 void GamePauseScreen::sendMessage(const char *message, const char *value) {
 	// Since the language message isn't allowed to be in native, we have to have add this
 	// to every screen which directly inherits from UIScreen(which are few right now, luckily).
@@ -820,3 +832,58 @@ void GamePauseScreen::sendMessage(const char *message, const char *value) {
 		screenManager()->RecreateAllViews();
 	}
 }
+
+void UmdReplaceScreen::CreateViews() {
+	I18NCategory *m = GetI18NCategory("MainMenu");
+
+	TabHolder *leftColumn = new TabHolder(ORIENT_HORIZONTAL, 64);
+	leftColumn->SetClip(true);
+
+	ScrollView *scrollRecentGames = new ScrollView(ORIENT_VERTICAL, new LinearLayoutParams(FILL_PARENT, WRAP_CONTENT));
+	ScrollView *scrollAllGames = new ScrollView(ORIENT_VERTICAL, new LinearLayoutParams(FILL_PARENT, WRAP_CONTENT));
+
+	GameBrowser *tabRecentGames = new GameBrowser(
+		"!RECENT", false, &g_Config.bGridView1, "", "",
+		new LinearLayoutParams(FILL_PARENT, FILL_PARENT));
+	GameBrowser *tabAllGames = new GameBrowser(g_Config.currentDirectory, true, &g_Config.bGridView2, 
+		m->T("How to get games"), "http://www.ppsspp.org/getgames.html",
+		new LinearLayoutParams(FILL_PARENT, FILL_PARENT));
+
+	scrollRecentGames->Add(tabRecentGames);
+	scrollAllGames->Add(tabAllGames);
+
+	leftColumn->AddTab(m->T("Recent"), scrollRecentGames);
+	leftColumn->AddTab(m->T("Games"), scrollAllGames);
+
+	tabRecentGames->OnChoice.Handle(this, &UmdReplaceScreen::OnGameSelectedInstant);
+	tabAllGames->OnChoice.Handle(this, &UmdReplaceScreen::OnGameSelectedInstant);
+	tabRecentGames->OnHoldChoice.Handle(this, &UmdReplaceScreen::OnGameSelected);
+	tabAllGames->OnHoldChoice.Handle(this, &UmdReplaceScreen::OnGameSelected);
+
+	if (g_Config.recentIsos.size() > 0) {
+		leftColumn->SetCurrentTab(0);
+	}else{
+		leftColumn->SetCurrentTab(1);
+	}
+
+	root_ = new LinearLayout(ORIENT_HORIZONTAL);
+	leftColumn->ReplaceLayoutParams(new LinearLayoutParams(1.0));
+	root_->Add(leftColumn);	
+}
+
+void UmdReplaceScreen::update(InputState &input) {
+	UpdateUIState(UISTATE_PAUSEMENU);
+	UIScreen::update(input);
+}
+
+UI::EventReturn UmdReplaceScreen::OnGameSelected(UI::EventParams &e) {
+	__UmdReplace(e.s);
+	screenManager()->finishDialog(this, DR_OK);
+	return UI::EVENT_DONE;
+}
+
+UI::EventReturn UmdReplaceScreen:: OnGameSelectedInstant(UI::EventParams &e) {
+	__UmdReplace(e.s);
+	screenManager()->finishDialog(this, DR_OK);
+	return UI::EVENT_DONE;
+}
diff --git a/UI/MainScreen.h b/UI/MainScreen.h
index 308f86473c..0a7c432b7f 100644
--- a/UI/MainScreen.h
+++ b/UI/MainScreen.h
@@ -80,9 +80,25 @@ private:
 	UI::EventReturn OnStateSelected(UI::EventParams &e);
 	UI::EventReturn OnCwCheat(UI::EventParams &e);
 
+	UI::EventReturn OnSwitchUMD(UI::EventParams &e);
+
 	std::string gamePath_;
 
 	UI::ChoiceStrip *saveSlots_;
 	UI::Choice *saveStateButton_;
 	UI::Choice *loadStateButton_;
 };
+
+class UmdReplaceScreen : public UIDialogScreenWithBackground {
+public:
+	UmdReplaceScreen() {}
+
+protected:
+	virtual void CreateViews();
+	virtual void update(InputState &input);
+	//virtual void sendMessage(const char *message, const char *value);
+
+private:
+	UI::EventReturn OnGameSelected(UI::EventParams &e);
+	UI::EventReturn OnGameSelectedInstant(UI::EventParams &e);
+};