diff --git a/cmd/launcher/CAddScreen.cpp b/cmd/launcher/CAddScreen.cpp
index bc65f283..5a876b77 100644
--- a/cmd/launcher/CAddScreen.cpp
+++ b/cmd/launcher/CAddScreen.cpp
@@ -70,7 +70,7 @@ CAddScreen::doModal()
 {
 	// do dialog
 	return (DialogBoxParam(s_instance, MAKEINTRESOURCE(IDD_ADD),
-								m_parent, dlgProc, (LPARAM)this) != 0);
+								m_parent, (DLGPROC)dlgProc, (LPARAM)this) != 0);
 }
 
 CString
diff --git a/cmd/launcher/CAdvancedOptions.cpp b/cmd/launcher/CAdvancedOptions.cpp
index ee5b45ea..c1ea83ef 100644
--- a/cmd/launcher/CAdvancedOptions.cpp
+++ b/cmd/launcher/CAdvancedOptions.cpp
@@ -54,7 +54,7 @@ CAdvancedOptions::doModal(bool isClient)
 
 	// do dialog
 	DialogBoxParam(s_instance, MAKEINTRESOURCE(IDD_ADVANCED_OPTIONS),
-								m_parent, dlgProc, (LPARAM)this);
+								m_parent, (DLGPROC)dlgProc, (LPARAM)this);
 }
 
 CString
diff --git a/cmd/launcher/CAutoStart.cpp b/cmd/launcher/CAutoStart.cpp
index 7b390a58..eb18a6b0 100644
--- a/cmd/launcher/CAutoStart.cpp
+++ b/cmd/launcher/CAutoStart.cpp
@@ -87,7 +87,7 @@ CAutoStart::doModal()
 
 	// do dialog
 	DialogBoxParam(s_instance, MAKEINTRESOURCE(IDD_AUTOSTART),
-								m_parent, dlgProc, (LPARAM)this);
+								m_parent, (DLGPROC)dlgProc, (LPARAM)this);
 
 	// remove log outputter
 	CLOG->pop_front();
diff --git a/cmd/launcher/CGlobalOptions.cpp b/cmd/launcher/CGlobalOptions.cpp
index b7c15801..8237a07f 100644
--- a/cmd/launcher/CGlobalOptions.cpp
+++ b/cmd/launcher/CGlobalOptions.cpp
@@ -50,7 +50,7 @@ CGlobalOptions::doModal()
 {
 	// do dialog
 	DialogBoxParam(s_instance, MAKEINTRESOURCE(IDD_GLOBAL_OPTIONS),
-								m_parent, dlgProc, (LPARAM)this);
+								m_parent, (DLGPROC)dlgProc, (LPARAM)this);
 }
 
 void
diff --git a/cmd/launcher/CHotkeyOptions.cpp b/cmd/launcher/CHotkeyOptions.cpp
index 7e7a1b56..5b71d4ae 100644
--- a/cmd/launcher/CHotkeyOptions.cpp
+++ b/cmd/launcher/CHotkeyOptions.cpp
@@ -53,7 +53,7 @@ CHotkeyOptions::doModal()
 	// do dialog
 	m_inputFilter = m_config->getInputFilter();
 	DialogBoxParam(s_instance, MAKEINTRESOURCE(IDD_HOTKEY_OPTIONS),
-								m_parent, dlgProc, (LPARAM)this);
+								m_parent, (DLGPROC)dlgProc, (LPARAM)this);
 }
 
 void
diff --git a/cmd/launcher/CInfo.cpp b/cmd/launcher/CInfo.cpp
index f2292db8..669da0e2 100644
--- a/cmd/launcher/CInfo.cpp
+++ b/cmd/launcher/CInfo.cpp
@@ -43,7 +43,7 @@ CInfo::doModal()
 {
 	// do dialog
 	DialogBoxParam(s_instance, MAKEINTRESOURCE(IDD_INFO),
-								m_parent, dlgProc, (LPARAM)this);
+								m_parent, (DLGPROC)dlgProc, (LPARAM)this);
 }
 
 void
diff --git a/cmd/launcher/CScreensLinks.cpp b/cmd/launcher/CScreensLinks.cpp
index dbbca67b..c7e58a04 100644
--- a/cmd/launcher/CScreensLinks.cpp
+++ b/cmd/launcher/CScreensLinks.cpp
@@ -59,7 +59,7 @@ CScreensLinks::doModal()
 {
 	// do dialog
 	DialogBoxParam(s_instance, MAKEINTRESOURCE(IDD_SCREENS_LINKS),
-								m_parent, dlgProc, (LPARAM)this);
+								m_parent, (DLGPROC)dlgProc, (LPARAM)this);
 }
 
 void
diff --git a/cmd/launcher/launcher.cpp b/cmd/launcher/launcher.cpp
index 07eab676..938822da 100644
--- a/cmd/launcher/launcher.cpp
+++ b/cmd/launcher/launcher.cpp
@@ -379,7 +379,7 @@ waitForChild(HWND hwnd, HANDLE thread, DWORD threadID)
 
 	// do dialog that let's the user terminate the test
 	DialogBoxParam(s_instance, MAKEINTRESOURCE(IDD_WAIT), hwnd,
-								waitDlgProc, (LPARAM)&info);
+								(DLGPROC)waitDlgProc, (LPARAM)&info);
 
 	// force the waiter thread to finish and wait for it
 	SetEvent(info.m_ready);
diff --git a/cmd/synergyc/CMSWindowsClientTaskBarReceiver.cpp b/cmd/synergyc/CMSWindowsClientTaskBarReceiver.cpp
index 5c31f4a5..c002b9f1 100644
--- a/cmd/synergyc/CMSWindowsClientTaskBarReceiver.cpp
+++ b/cmd/synergyc/CMSWindowsClientTaskBarReceiver.cpp
@@ -272,15 +272,15 @@ CMSWindowsClientTaskBarReceiver::createWindow()
 	m_window = CreateDialogParam(m_appInstance,
 							MAKEINTRESOURCE(IDD_TASKBAR_STATUS),
 							NULL,
-							&CMSWindowsClientTaskBarReceiver::staticDlgProc,
+							(DLGPROC)&CMSWindowsClientTaskBarReceiver::staticDlgProc,
 							reinterpret_cast<LPARAM>(
 								reinterpret_cast<void*>(this)));
 
 	// window should appear on top of everything, including (especially)
 	// the task bar.
-	DWORD style = GetWindowLong(m_window, GWL_EXSTYLE);
+	LONG_PTR style = GetWindowLongPtr(m_window, GWL_EXSTYLE);
 	style |= WS_EX_TOOLWINDOW | WS_EX_TOPMOST;
-	SetWindowLong(m_window, GWL_EXSTYLE, style);
+	SetWindowLongPtr(m_window, GWL_EXSTYLE, style);
 
 	// tell the task bar about this dialog
 	CArchTaskBarWindows::addDialog(m_window);
diff --git a/cmd/synergys/CMSWindowsServerTaskBarReceiver.cpp b/cmd/synergys/CMSWindowsServerTaskBarReceiver.cpp
index 21a61954..e332ccea 100644
--- a/cmd/synergys/CMSWindowsServerTaskBarReceiver.cpp
+++ b/cmd/synergys/CMSWindowsServerTaskBarReceiver.cpp
@@ -300,15 +300,15 @@ CMSWindowsServerTaskBarReceiver::createWindow()
 	m_window = CreateDialogParam(m_appInstance,
 							MAKEINTRESOURCE(IDD_TASKBAR_STATUS),
 							NULL,
-							&CMSWindowsServerTaskBarReceiver::staticDlgProc,
+							(DLGPROC)&CMSWindowsServerTaskBarReceiver::staticDlgProc,
 							reinterpret_cast<LPARAM>(
 								reinterpret_cast<void*>(this)));
 
 	// window should appear on top of everything, including (especially)
 	// the task bar.
-	DWORD style = GetWindowLong(m_window, GWL_EXSTYLE);
+	LONG_PTR style = GetWindowLongPtr(m_window, GWL_EXSTYLE);
 	style |= WS_EX_TOOLWINDOW | WS_EX_TOPMOST;
-	SetWindowLong(m_window, GWL_EXSTYLE, style);
+	SetWindowLongPtr(m_window, GWL_EXSTYLE, style);
 
 	// tell the task bar about this dialog
 	CArchTaskBarWindows::addDialog(m_window);
@@ -353,11 +353,11 @@ CMSWindowsServerTaskBarReceiver::staticDlgProc(HWND hwnd,
 	if (msg == WM_INITDIALOG) {
 		self = reinterpret_cast<CMSWindowsServerTaskBarReceiver*>(
 							reinterpret_cast<void*>(lParam));
-		SetWindowLong(hwnd, GWL_USERDATA, lParam);
+		SetWindowLongPtr(hwnd, GWLP_USERDATA, lParam);
 	}
 	else {
 		// get the extra window data and forward the call
-		LONG data = GetWindowLong(hwnd, GWL_USERDATA);
+		LONG data = GetWindowLongPtr(hwnd, GWLP_USERDATA);
 		if (data != 0) {
 			self = reinterpret_cast<CMSWindowsServerTaskBarReceiver*>(
 							reinterpret_cast<void*>(data));
diff --git a/lib/platform/CMSWindowsScreenSaver.cpp b/lib/platform/CMSWindowsScreenSaver.cpp
index 529cd176..7217338f 100644
--- a/lib/platform/CMSWindowsScreenSaver.cpp
+++ b/lib/platform/CMSWindowsScreenSaver.cpp
@@ -294,7 +294,7 @@ BOOL CALLBACK
 CMSWindowsScreenSaver::killScreenSaverFunc(HWND hwnd, LPARAM arg)
 {
 	if (IsWindowVisible(hwnd)) {
-		HINSTANCE instance = (HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE);
+		HINSTANCE instance = (HINSTANCE)GetWindowLongPtr(hwnd, GWLP_HINSTANCE);
 		if (instance != CMSWindowsScreen::getInstance()) {
 			PostMessage(hwnd, WM_CLOSE, 0, 0);
 			*reinterpret_cast<bool*>(arg) = true;