diff --git a/projects/openrct2.vcxproj b/projects/openrct2.vcxproj
index a9edfa7b23..c53fa7bbb8 100644
--- a/projects/openrct2.vcxproj
+++ b/projects/openrct2.vcxproj
@@ -36,7 +36,9 @@
     <ClInclude Include="..\lib\libspeex\speex\speex_types.h" />
     <ClInclude Include="..\lib\libspeex\stack_alloc.h" />
     <ClInclude Include="..\lib\lodepng\lodepng.h" />
-    <ClCompile Include="..\lib\argparse\argparse.c" />
+    <ClCompile Include="..\lib\argparse\argparse.c">
+      <WarningLevel Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">TurnOffAllWarnings</WarningLevel>
+    </ClCompile>
     <ClCompile Include="..\lib\libspeex\resample.c;..\lib\lodepng\lodepng.c">
       <WarningLevel Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">TurnOffAllWarnings</WarningLevel>
     </ClCompile>
diff --git a/projects/openrct2.vcxproj.filters b/projects/openrct2.vcxproj.filters
index f8cb1164cc..c18e8cbaab 100644
--- a/projects/openrct2.vcxproj.filters
+++ b/projects/openrct2.vcxproj.filters
@@ -369,7 +369,6 @@
       <Filter>Source\Windows</Filter>
     </ClCompile>
     <ClCompile Include="..\lib\lodepng\lodepng.c" />
-    <ClCompile Include="..\lib\lodepng\lodepng.c" />
     <ClCompile Include="..\src\windows\shortcut_key_change.c">
       <Filter>Source\Windows</Filter>
     </ClCompile>
@@ -382,9 +381,6 @@
     <ClCompile Include="..\lib\lodepng\lodepng.c" />
     <ClCompile Include="..\lib\lodepng\lodepng.c" />
     <ClCompile Include="..\lib\lodepng\lodepng.c" />
-    <ClCompile Include="..\lib\libspeex\resample.c">
-      <Filter>Libraries\lodepng</Filter>
-    </ClCompile>
     <ClCompile Include="..\lib\lodepng\lodepng.c" />
     <ClCompile Include="..\lib\lodepng\lodepng.c" />
     <ClCompile Include="..\lib\libspeex\resample.c">
@@ -425,6 +421,7 @@
     <ClCompile Include="..\lib\argparse\argparse.c">
       <Filter>Libraries\argparse</Filter>
     </ClCompile>
+    <ClCompile Include="..\lib\libspeex\resample.c;..\lib\lodepng\lodepng.c" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\src\management\award.h">
diff --git a/projects/openrct2.vcxproj.user b/projects/openrct2.vcxproj.user
index 3695926811..d08f3ad23c 100644
--- a/projects/openrct2.vcxproj.user
+++ b/projects/openrct2.vcxproj.user
@@ -12,6 +12,7 @@
     <LocalDebuggerCommand>$(TargetDir)\openrct2.exe</LocalDebuggerCommand>
     <LocalDebuggerWorkingDirectory>$(TargetDir)</LocalDebuggerWorkingDirectory>
     <DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>
-    <LocalDebuggerCommandArguments>"C:\Users\Ted\Documents\OpenRCT2\scenarios\RCT Forest Frontiers.SC6"</LocalDebuggerCommandArguments>
+    <LocalDebuggerCommandArguments>
+    </LocalDebuggerCommandArguments>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/audio/mixer.cpp b/src/audio/mixer.cpp
index f71c7bda8e..8b46d05086 100644
--- a/src/audio/mixer.cpp
+++ b/src/audio/mixer.cpp
@@ -20,11 +20,11 @@
 
 #include <math.h>
 #include <SDL.h>
-#include <string.h>
 
 extern "C" {
-#include "../config.h"
-#include "audio.h"
+	#include "../config.h"
+	#include "../platform/platform.h"
+	#include "audio.h"
 }
 #include "mixer.h"
 
diff --git a/src/cmdline.c b/src/cmdline.c
index 6c24be9d61..10c08c9eef 100644
--- a/src/cmdline.c
+++ b/src/cmdline.c
@@ -18,7 +18,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *****************************************************************************/
 
-#include <string.h>
 #ifdef _MSC_VER
 #include <time.h>
 #endif
@@ -26,7 +25,7 @@
 #include "addresses.h"
 #include "cmdline.h"
 #include "openrct2.h"
-#include "platform/osinterface.h"
+#include "platform/platform.h"
 
 typedef struct tm tm_t;
 typedef struct argparse_option argparse_option_t;
@@ -83,7 +82,7 @@ int cmdline_run(char *argv[], int argc)
 			if (argc >= 2)
 				strcpy(gOpenRCT2StartupActionPath, argv[1]);
 		} else {
-			if (osinterface_file_exists(argv[0])) {
+			if (platform_file_exists(argv[0])) {
 				gOpenRCT2StartupAction = STARTUP_ACTION_OPEN;
 				strcpy(gOpenRCT2StartupActionPath, argv[0]);
 			} else {
diff --git a/src/config.c b/src/config.c
index 4200d613c4..e3c9852034 100644
--- a/src/config.c
+++ b/src/config.c
@@ -18,13 +18,13 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *****************************************************************************/
 
-#include <stdio.h>
 #include <SDL_keycode.h>
 #include <ctype.h>
 #include "addresses.h"
 #include "config.h"
 #include "localisation/localisation.h"
 #include "platform/osinterface.h"
+#include "platform/platform.h"
 
 // Current keyboard shortcuts
 uint16 gShortcutKeys[SHORTCUT_COUNT];
@@ -399,7 +399,7 @@ void config_init()
 	memcpy(&gGeneral_config, &gGeneral_config_default, sizeof(general_configuration_t));
 
 	if (strcmp(path, "") != 0){
-		if (!osinterface_ensure_directory_exists(path)) {
+		if (!platform_ensure_directory_exists(path)) {
 			config_error("Could not create config file (do you have write access to your documents folder?)");
 			return;
 		}
@@ -443,7 +443,7 @@ static int config_find_rct2_path(char *resultPath)
 	};
 
 	for (i = 0; i < countof(searchLocations); i++) {
-		if ( osinterface_directory_exists(searchLocations[i]) ) {
+		if (platform_directory_exists(searchLocations[i]) ) {
 			strcpy(resultPath, searchLocations[i]);
 			return 1;
 		}
diff --git a/src/config.h b/src/config.h
index 6092481635..cb7c47648d 100644
--- a/src/config.h
+++ b/src/config.h
@@ -21,9 +21,9 @@
 #ifndef _CONFIG_H_
 #define _CONFIG_H_
 
-#include <windows.h> // for MAX_PATH
 #include "common.h"
 #include "localisation/currency.h"
+#include "platform/platform.h"
 
 enum {
 	CONFIG_FLAG_ALWAYS_SHOW_GRIDLINES = (1 << 0),
diff --git a/src/interface/screenshot.c b/src/interface/screenshot.c
index 5f871f609b..1a8bb459d8 100644
--- a/src/interface/screenshot.c
+++ b/src/interface/screenshot.c
@@ -19,20 +19,17 @@
  *****************************************************************************/
 #pragma pack(1)
 
-#include <windows.h> // For MAX_PATH
 #include <lodepng/lodepng.h>
-#include <stdio.h>
-#include "../platform/osinterface.h"
 #include "../addresses.h"
 #include "../config.h"
 #include "../drawing/drawing.h"
 #include "../game.h"
 #include "../localisation/localisation.h"
+#include "../platform/osinterface.h"
+#include "../platform/platform.h"
 #include "../windows/error.h"
 #include "screenshot.h"
 
-
-
 static int screenshot_dump_bmp();
 static int screenshot_dump_png();
 
@@ -63,7 +60,7 @@ void screenshot_check()
 static int screenshot_get_next_path(char *path, char *extension)
 {
 	char *screenshotPath = osinterface_get_orct2_homesubfolder("screenshot");
-	if (!osinterface_ensure_directory_exists(screenshotPath)) {
+	if (!platform_ensure_directory_exists(screenshotPath)) {
 		free(screenshotPath);
 
 		fprintf(stderr, "Unable to save screenshots in OpenRCT2 screenshot directory.\n");
@@ -77,7 +74,7 @@ static int screenshot_get_next_path(char *path, char *extension)
 		// Glue together path and filename
 		sprintf(path, "%s%cSCR%d%s", screenshotPath, osinterface_get_path_separator(), i, extension);
 
-		if (!osinterface_file_exists(path)) {
+		if (!platform_file_exists(path)) {
 			return i;
 		}
 	}
diff --git a/src/object.c b/src/object.c
index a4644602f7..0882307d35 100644
--- a/src/object.c
+++ b/src/object.c
@@ -18,14 +18,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *****************************************************************************/
 
-#include <memory.h>
-#include <stdio.h>
-#include <string.h>
 #include <ctype.h>
 #include "addresses.h"
 #include "localisation/localisation.h"
 #include "object.h"
 #include "platform/osinterface.h"
+#include "platform/platform.h"
 #include "util/sawyercoding.h"
 
 int object_entry_compare(rct_object_entry *a, rct_object_entry *b);
@@ -251,7 +249,7 @@ int object_load_packed(FILE *file)
 	strcat(path, ".DAT");
 
 	// 
-	for (; osinterface_file_exists(path);){
+	for (; platform_file_exists(path);){
 		for (char* curr_char = last_char - 1;; --curr_char){
 			if (*curr_char == '\\'){
 				subsitute_path(path, RCT2_ADDRESS(RCT2_ADDRESS_OBJECT_DATA_PATH, char), "00000000.DAT");
diff --git a/src/object.h b/src/object.h
index b0e125ae8d..a28f47a48f 100644
--- a/src/object.h
+++ b/src/object.h
@@ -21,8 +21,7 @@
 #ifndef _OBJECT_H_
 #define _OBJECT_H_
 
-#include <stdio.h>
-#include "rct2.h"
+#include "common.h"
 
 /**
  * Object entry structure.
diff --git a/src/openrct2.c b/src/openrct2.c
index 8e19f18543..d895bd826d 100644
--- a/src/openrct2.c
+++ b/src/openrct2.c
@@ -26,6 +26,7 @@
 #include "editor.h"
 #include "localisation/localisation.h"
 #include "openrct2.h"
+#include "platform/platform.h"
 #include "platform/osinterface.h"
 
 int gOpenRCT2StartupAction = STARTUP_ACTION_TITLE;
@@ -36,11 +37,18 @@ char gOpenRCT2StartupActionPath[512] = { 0 };
  */
 void openrct2_launch()
 {
+	config_init();
+
+	// TODO add configuration option to allow multiple instances
+	if (!platform_lock_single_instance()) {
+		fprintf(stderr, "OpenRCT2 is already running.\n");
+		return;
+	}
+
 	get_system_info();
 	audio_init();
 	audio_get_devices();
 	get_dsound_devices();
-	config_init();
 	language_open(gGeneral_config.language);
 	rct2_init();
 	Mixer_Init(NULL);
diff --git a/src/platform/osinterface.c b/src/platform/osinterface.c
index de2a92a862..4cb7af32aa 100644
--- a/src/platform/osinterface.c
+++ b/src/platform/osinterface.c
@@ -851,25 +851,6 @@ char *osinterface_get_orct2_homesubfolder(const char *subFolder)
 	return path;
 }
 
-int osinterface_file_exists(const char *path)
-{
-	return !(GetFileAttributes(path) == INVALID_FILE_ATTRIBUTES && GetLastError() == ERROR_FILE_NOT_FOUND);
-}
-
-int osinterface_directory_exists(const char *path)
-{
-	DWORD dwAttrib = GetFileAttributes(path);
-	return dwAttrib != INVALID_FILE_ATTRIBUTES && (dwAttrib & FILE_ATTRIBUTE_DIRECTORY);
-}
-
-int osinterface_ensure_directory_exists(const char *path)
-{
-	if (osinterface_directory_exists(path))
-		return 1;
-
-	return CreateDirectory(path, NULL);
-}
-
 char osinterface_get_path_separator()
 {
 	return '\\';
diff --git a/src/platform/osinterface.h b/src/platform/osinterface.h
index d88eead8bc..fa02afb3dd 100644
--- a/src/platform/osinterface.h
+++ b/src/platform/osinterface.h
@@ -107,9 +107,6 @@ char* osinterface_open_directory_browser(char *title);
 
 char* osinterface_get_orct2_homefolder();
 char *osinterface_get_orct2_homesubfolder(const char *subFolder);
-int osinterface_file_exists(const char *path);
-int osinterface_directory_exists(const char *path);
-int osinterface_ensure_directory_exists(const char *path);
 
 char osinterface_get_path_separator();
 int osinterface_scancode_to_rct_keycode(int sdl_key);
diff --git a/src/platform/platform.h b/src/platform/platform.h
index 88678c3ec8..63d1806aa2 100644
--- a/src/platform/platform.h
+++ b/src/platform/platform.h
@@ -21,10 +21,15 @@
 #ifndef _PLATFORM_H_
 #define _PLATFORM_H_
 
+#ifndef MAX_PATH
+#define MAX_PATH 260
+#endif
 
 // Platform specific definitions
 char platform_get_path_separator();
+int platform_file_exists(const char *path);
 int platform_directory_exists(const char *path);
 int platform_ensure_directory_exists(const char *path);
+int platform_lock_single_instance();
 
 #endif
\ No newline at end of file
diff --git a/src/platform/windows.c b/src/platform/windows.c
index 1de14e0272..30b2b3f5b8 100644
--- a/src/platform/windows.c
+++ b/src/platform/windows.c
@@ -25,6 +25,9 @@
 #include "../cmdline.h"
 #include "../openrct2.h"
 
+// The name of the mutex used to prevent multiple instances of the game from running
+#define SINGLE_INSTANCE_MUTEX_NAME "RollerCoaster Tycoon 2_GSKMUTEX"
+
 LPSTR *CommandLineToArgvA(LPSTR lpCmdLine, int *argc);
 
 /**
@@ -79,6 +82,11 @@ char platform_get_path_separator()
 	return '\\';
 }
 
+int platform_file_exists(const char *path)
+{
+	return !(GetFileAttributes(path) == INVALID_FILE_ATTRIBUTES && GetLastError() == ERROR_FILE_NOT_FOUND);
+}
+
 int platform_directory_exists(const char *path)
 {
 	DWORD dwAttrib = GetFileAttributes(path);
@@ -93,6 +101,26 @@ int platform_ensure_directory_exists(const char *path)
 	return CreateDirectory(path, NULL);
 }
 
+int platform_lock_single_instance()
+{
+	HANDLE mutex, status;
+
+	// Check if operating system mutex exists
+	mutex = OpenMutex(MUTEX_ALL_ACCESS, FALSE, SINGLE_INSTANCE_MUTEX_NAME);
+	if (mutex == NULL) {
+		// Create new mutex
+		status = CreateMutex(NULL, FALSE, SINGLE_INSTANCE_MUTEX_NAME);
+		if (status == NULL)
+			fprintf(stderr, "unable to create mutex\n");
+
+		return 1;
+	} else {
+		// Already running
+		CloseHandle(mutex);
+		return 0;
+	}
+}
+
 /**
  * http://alter.org.ua/en/docs/win/args/
  */
diff --git a/src/rct2.c b/src/rct2.c
index d6c13feee2..9e2c009178 100644
--- a/src/rct2.c
+++ b/src/rct2.c
@@ -20,7 +20,6 @@
 
 #pragma warning(disable : 4996) // GetVersionExA deprecated
 
-#include <string.h>
 #include <setjmp.h>
 #ifdef _MSC_VER
 #include <time.h>
@@ -42,6 +41,7 @@
 #include "management/news_item.h"
 #include "object.h"
 #include "platform/osinterface.h"
+#include "platform/platform.h"
 #include "ride/ride.h"
 #include "ride/track.h"
 #include "scenario.h"
@@ -147,7 +147,7 @@ void rct2_init()
 void rct2_init_directories()
 {
 	// check install directory
-	if ( !osinterface_directory_exists(gGeneral_config.game_path) ) {
+	if (!platform_directory_exists(gGeneral_config.game_path) ) {
 		osinterface_show_messagebox("Invalid RCT2 installation path. Please correct in config.ini.");
 		exit(-1);
 	}
@@ -186,13 +186,6 @@ void subsitute_path(char *dest, const char *path, const char *filename)
 // rct2: 0x00674B42
 void rct2_startup_checks()
 {
-	// Check if game is already running
-	if (check_mutex())
-	{
-		RCT2_ERROR("Game is already running");
-		RCT2_CALLPROC_X(0x006E3838, 0x343, 0xB2B, 0, 0, 0, 0, 0); // exit_with_error
-	}
-
 	// Check data files
 	check_file_paths();
 	check_files_integrity();
@@ -241,24 +234,6 @@ int rct2_open_file(const char *path)
 	return 0;
 }
 
-// rct2: 0x00407DB0
-int check_mutex()
-{
-	const char * const mutex_name = "RollerCoaster Tycoon 2_GSKMUTEX"; // rct2 @ 0x009AAC3D + 0x009A8B50
-
-	HANDLE mutex = OpenMutex(MUTEX_ALL_ACCESS, FALSE, mutex_name);
-
-	if (mutex != NULL)
-	{
-		// Already running
-		CloseHandle(mutex);
-		return 1;
-	}
-
-	HANDLE status = CreateMutex(NULL, FALSE, mutex_name);
-	return 0;
-}
-
 // rct2: 0x00674C95
 void check_file_paths()
 {
diff --git a/src/rct2.h b/src/rct2.h
index 85d13baf0e..b8e6d10a2e 100644
--- a/src/rct2.h
+++ b/src/rct2.h
@@ -25,6 +25,7 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 
 typedef signed char sint8;
 typedef signed short sint16;
diff --git a/src/scenario.c b/src/scenario.c
index f1659be109..04494a2cc4 100644
--- a/src/scenario.c
+++ b/src/scenario.c
@@ -19,7 +19,6 @@
  *****************************************************************************/
 
 #include <windows.h>
-#include <string.h>
 #include "addresses.h"
 #include "game.h"
 #include "interface/viewport.h"
diff --git a/src/title.c b/src/title.c
index de0ccf685d..07ab525ef0 100644
--- a/src/title.c
+++ b/src/title.c
@@ -19,7 +19,6 @@
 *****************************************************************************/
 
 #include <windows.h>
-#include <string.h>
 #include <time.h>
 #include "addresses.h"
 #include "audio/audio.h"
diff --git a/src/tutorial.c b/src/tutorial.c
index fe42977286..5fc7972287 100644
--- a/src/tutorial.c
+++ b/src/tutorial.c
@@ -18,7 +18,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *****************************************************************************/
 
-#include <string.h>
 #include "addresses.h"
 #include "localisation/localisation.h"
 #include "tutorial.h"