diff --git a/Jones3D/Display/JonesHud.c b/Jones3D/Display/JonesHud.c
index d2b8b0bb8..bda981723 100644
--- a/Jones3D/Display/JonesHud.c
+++ b/Jones3D/Display/JonesHud.c
@@ -5,8 +5,8 @@
 
 #include <Jones3D/Display/jonesConfig.h>
 #include <Jones3D/Display/JonesReticle.h>
-#include <Jones3D/Main/jonesLevel.h>
-#include <Jones3D/Main/jonesMain.h>
+#include <Jones3D/Main/JonesLevel.h>
+#include <Jones3D/Main/JonesMain.h>
 #include <Jones3D/Main/jonesString.h>
 #include <Jones3D/Play/jonesCog.h>
 #include <Jones3D/Play/jonesInventory.h>
diff --git a/Jones3D/Display/JonesReticle.c b/Jones3D/Display/JonesReticle.c
index 105844f35..94e50aaf7 100644
--- a/Jones3D/Display/JonesReticle.c
+++ b/Jones3D/Display/JonesReticle.c
@@ -123,7 +123,7 @@ JonesAimReticle JonesReticle_reticle = { 0 };
 
 
 // Add to stdColor.h or a utility header
-inline rdVector4 JonesReticle_ColorToVector4(tStdColor color)
+static inline rdVector4 JonesReticle_ColorToVector4(tStdColor color)
 {
     rdVector4 result;
     result.red   = STD_GETRED(color) / 255.0f;
@@ -133,7 +133,7 @@ inline rdVector4 JonesReticle_ColorToVector4(tStdColor color)
     return result;
 }
 
-inline tStdColor JonesReticle_ColorFromVector4(const rdVector4* pVector)
+static inline tStdColor JonesReticle_ColorFromVector4(const rdVector4* pVector)
 {
     return STD_RGBA(
         (uint8_t)(pVector->red * 255.0f),
@@ -275,7 +275,7 @@ bool JonesReticle_IsEnabled(void)
 /**
 * Calculate easing function for smooth animation(ease - out)
 */
-inline float J3DAPI JonesReticle_EaseOut(float t)
+static inline float J3DAPI JonesReticle_EaseOut(float t)
 {
     // Ease out cubic: 1 - (1-t)^3
     float oneMinusT = 1.0f - t;
diff --git a/Jones3D/Display/jonesConfig.c b/Jones3D/Display/jonesConfig.c
index 510532d16..109ed3eb9 100644
--- a/Jones3D/Display/jonesConfig.c
+++ b/Jones3D/Display/jonesConfig.c
@@ -19,7 +19,7 @@
 
 #include <sith/Devices/sithControl.h>
 #include <sith/Devices/sithSoundMixer.h>
-#include <sith/DSS/sithGamesave.h>
+#include <sith/Dss/sithGamesave.h>
 #include <sith/Engine/sithRender.h>
 #include <sith/Gameplay/sithOverlayMap.h>
 #include <sith/Gameplay/sithPlayer.h>
diff --git a/Jones3D/Main/JonesLevel.h b/Jones3D/Main/JonesLevel.h
index 84ec0b305..7afad30c9 100644
--- a/Jones3D/Main/JonesLevel.h
+++ b/Jones3D/Main/JonesLevel.h
@@ -309,7 +309,7 @@ static const JonesLevelInfo JonesMain_aNdyLevelLoadInfos[JONESLEVEL_NUMLEVELS] =
     }
 };
 
-inline bool J3DAPI JonesLevel_IsValidLevelNum(size_t levelNum)
+static inline bool J3DAPI JonesLevel_IsValidLevelNum(size_t levelNum)
 {
     if ( levelNum != JONESLEVEL_GENERICLEVELNUM && levelNum < JONESLEVEL_NUMLEVELS ) {
         return true;
diff --git a/Jones3D/Main/JonesMain.c b/Jones3D/Main/JonesMain.c
index ad968a410..8d428ce8e 100644
--- a/Jones3D/Main/JonesMain.c
+++ b/Jones3D/Main/JonesMain.c
@@ -18,8 +18,8 @@
 #include <rdroid/Primitives/rdFont.h>
 #include <rdroid/Raster/rdCache.h>
 
-#include <sith/DSS/sithDSS.h>
-#include <sith/DSS/sithGamesave.h>
+#include <sith/Dss/sithDSS.h>
+#include <sith/Dss/sithGamesave.h>
 #include <sith/Devices/sithComm.h>
 #include <sith/Devices/sithConsole.h>
 #include <sith/Devices/sithSound.h>
diff --git a/Jones3D/Play/JonesControl.c b/Jones3D/Play/JonesControl.c
index 42731603a..9bcfcf2da 100644
--- a/Jones3D/Play/JonesControl.c
+++ b/Jones3D/Play/JonesControl.c
@@ -1,7 +1,7 @@
 #include "JonesControl.h"
 #include <j3dcore/j3dhook.h>
 
-#include <Jones3D/Display/JonesConfig.h>
+#include <Jones3D/Display/jonesConfig.h>
 #include <Jones3D/Display/JonesConsole.h>
 #include <Jones3D/Main/JonesMain.h>
 #include <Jones3D/RTI/symbols.h>
diff --git a/Jones3D/types.h b/Jones3D/types.h
index c72fb7010..267fdc0c8 100644
--- a/Jones3D/types.h
+++ b/Jones3D/types.h
@@ -1,8 +1,8 @@
 #ifndef JONES3D_TYPES_H
 #define JONES3D_TYPES_H
 #define STRICT
-#include <Windows.h>
-#include <CommCtrl.h>
+#include <windows.h>
+#include <commctrl.h>
 #include <stdint.h>
 
 #include <j3dcore/j3d.h>
diff --git a/Libs/j3dcore/j3d.h.in b/Libs/j3dcore/j3d.h.in
index bdee6af18..7e135b72e 100644
--- a/Libs/j3dcore/j3d.h.in
+++ b/Libs/j3dcore/j3d.h.in
@@ -1,6 +1,7 @@
 
 #ifndef J3DCORE_H
 #define J3DCORE_H
+#include <assert.h> // static_assert on GCC/MinGW
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
@@ -51,7 +52,7 @@
 #       define STRICT
 #   endif
 #   define WIN32_LEAN_AND_MEAN
-#   include <Windows.h>
+#   include <windows.h>
 #   define strcmpi _strcmpi
 #   define strncmpi _strnicmp
 #   define wstrcmpi _wcsicmp
diff --git a/Libs/j3dcore/j3dhook.h b/Libs/j3dcore/j3dhook.h
index 05e17b393..02364fd49 100644
--- a/Libs/j3dcore/j3dhook.h
+++ b/Libs/j3dcore/j3dhook.h
@@ -97,7 +97,7 @@ J3D_EXTERN_C_START
  * @param endAddress The end address of the region to modify
  * @return true if successful, false otherwise
  */
-inline bool J3DStartHookContext(J3DHookContext* pCtx, uintptr_t startAddress, uintptr_t endAddress)
+static inline bool J3DStartHookContext(J3DHookContext* pCtx, uintptr_t startAddress, uintptr_t endAddress)
 {
     if ( endAddress <= startAddress ) {
         return false;
@@ -113,7 +113,7 @@ inline bool J3DStartHookContext(J3DHookContext* pCtx, uintptr_t startAddress, ui
  * @param pCtx The pointer to a J3DHookContext structure
  * @return true if successful, false otherwise
  */
-inline bool J3DEndHookContext(J3DHookContext* pCtx)
+static inline bool J3DEndHookContext(J3DHookContext* pCtx)
 {
     DWORD temp;
     return VirtualProtect((LPVOID)pCtx->startAddress, pCtx->size, pCtx->oldProtect, &temp);
diff --git a/Libs/rdroid/Engine/rdCamera.c b/Libs/rdroid/Engine/rdCamera.c
index 5aa0f1f09..687b3ade9 100644
--- a/Libs/rdroid/Engine/rdCamera.c
+++ b/Libs/rdroid/Engine/rdCamera.c
@@ -57,7 +57,7 @@ void rdCamera_ResetGlobals(void)
     memset(&rdCamera_g_camMatrix, 0, sizeof(rdCamera_g_camMatrix));
 }
 
-inline float rdCamera_ClampFOV(float fov)
+static inline float rdCamera_ClampFOV(float fov)
 {
     return STDMATH_CLAMP(fov, RDCAMERA_FOVMIN, RDCAMERA_FOVMAX);
 }
diff --git a/Libs/rdroid/Engine/rdQClip.c b/Libs/rdroid/Engine/rdQClip.c
index bb5555283..727aae1b1 100644
--- a/Libs/rdroid/Engine/rdQClip.c
+++ b/Libs/rdroid/Engine/rdQClip.c
@@ -3,7 +3,7 @@
 
 #include <rdroid/Engine/rdClip.h>
 #include <rdroid/Main/rdroid.h>
-#include <rdroid/Math/rdvector.h>
+#include <rdroid/Math/rdVector.h>
 #include <rdroid/RTI/symbols.h>
 
 #include <std/General/stdUtil.h>
diff --git a/Libs/rdroid/Raster/rdCache.c b/Libs/rdroid/Raster/rdCache.c
index 5b444dc0a..df9fa15bc 100644
--- a/Libs/rdroid/Raster/rdCache.c
+++ b/Libs/rdroid/Raster/rdCache.c
@@ -9,6 +9,7 @@
 #include <std/General/stdUtil.h>
 #include <std/Win95/std3D.h>
 
+#include <float.h>
 #include <math.h>
 #include <stdlib.h>
 
diff --git a/Libs/sith/Cog/sithCogFunctionSector.c b/Libs/sith/Cog/sithCogFunctionSector.c
index 60e54e01a..6ef817ca8 100644
--- a/Libs/sith/Cog/sithCogFunctionSector.c
+++ b/Libs/sith/Cog/sithCogFunctionSector.c
@@ -6,7 +6,7 @@
 #include <rdroid/Math/rdVector.h>
 
 #include <sith/Cog/sithCog.h>
-#include <sith/Cog/sithCogexec.h>
+#include <sith/Cog/sithCogExec.h>
 #include <sith/Engine/sithAnimate.h>
 #include <sith/World/sithSector.h>
 #include <sith/World/sithSurface.h>
diff --git a/Libs/sith/Cog/sithCogFunctionSound.c b/Libs/sith/Cog/sithCogFunctionSound.c
index 967495a34..5ed2860c7 100644
--- a/Libs/sith/Cog/sithCogFunctionSound.c
+++ b/Libs/sith/Cog/sithCogFunctionSound.c
@@ -3,7 +3,7 @@
 #include <sith/RTI/symbols.h>
 
 #include <sith/Cog/sithCog.h>
-#include <sith/Cog/sithCogexec.h>
+#include <sith/Cog/sithCogExec.h>
 #include <sith/Devices/sithComm.h>
 #include <sith/Devices/sithSound.h>
 #include <sith/Devices/sithSoundMixer.h>
diff --git a/Libs/sith/Cog/sithCogFunctionSurface.c b/Libs/sith/Cog/sithCogFunctionSurface.c
index 2d1d0a369..ceee4eeef 100644
--- a/Libs/sith/Cog/sithCogFunctionSurface.c
+++ b/Libs/sith/Cog/sithCogFunctionSurface.c
@@ -5,7 +5,7 @@
 #include <rdroid/Math/rdVector.h>
 
 #include <sith/Cog/sithCog.h>
-#include <sith/Cog/sithCogexec.h>
+#include <sith/Cog/sithCogExec.h>
 #include <sith/Engine/sithAnimate.h>
 #include <sith/World/sithSector.h>
 #include <sith/World/sithSurface.h>
diff --git a/Libs/sith/Dss/sithDSSCog.c b/Libs/sith/Dss/sithDSSCog.c
index 0d50ab20f..bae0b283a 100644
--- a/Libs/sith/Dss/sithDSSCog.c
+++ b/Libs/sith/Dss/sithDSSCog.c
@@ -2,7 +2,7 @@
 #include <j3dcore/j3dhook.h>
 
 #include <sith/Cog/sithCog.h>
-#include <sith/Dss/sithDss.h>
+#include <sith/Dss/sithDSS.h>
 #include <sith/Dss/sithMulti.h>
 #include <sith/RTI/symbols.h>
 #include <sith/World/sithThing.h>
diff --git a/Libs/sith/Main/sithCommand.h b/Libs/sith/Main/sithCommand.h
index e130dbd6b..a3f1e5288 100644
--- a/Libs/sith/Main/sithCommand.h
+++ b/Libs/sith/Main/sithCommand.h
@@ -14,7 +14,7 @@ J3D_EXTERN_C_START
 void sithCommand_RegisterCommands(void);
 
 
-inline bool sithCommand_ParseBool(const char* pStr, bool* pOut) // Added
+static inline bool sithCommand_ParseBool(const char* pStr, bool* pOut) // Added
 {
     if ( !pStr || !pOut ) {
         return false;
diff --git a/Libs/smush/Tests/SmushSoundTest.c b/Libs/smush/Tests/SmushSoundTest.c
index 9a0748bc4..2818764bf 100644
--- a/Libs/smush/Tests/SmushSoundTest.c
+++ b/Libs/smush/Tests/SmushSoundTest.c
@@ -7,9 +7,9 @@
 #include <string.h>
 
 #include <j3dcore/j3d.h>
-#include <Windows.h>
+#include <windows.h>
 #include <mmsystem.h>
-#include <Mmreg.h>
+#include <mmreg.h>
 #if defined (J3D_DIRECTX6)
 #include <DirectX6/dsound.h>
 #elif defined (J3D_DIRECTX9)
diff --git a/Libs/smush/insane/Sound/Dsnd.c b/Libs/smush/insane/Sound/Dsnd.c
index f7da18fe5..db5eba0c9 100644
--- a/Libs/smush/insane/Sound/Dsnd.c
+++ b/Libs/smush/insane/Sound/Dsnd.c
@@ -9,9 +9,9 @@
 #include <stddef.h>
 #include <string.h>
 
-#include <Windows.h>
+#include <windows.h>
 #include <mmsystem.h>
-#include <Mmreg.h>
+#include <mmreg.h>
 #include <sound/Driver.h>
 
 #include <smush/insane/Sound/Engine.h>
diff --git a/Libs/sound/types.h b/Libs/sound/types.h
index 059b1a676..7d5136881 100644
--- a/Libs/sound/types.h
+++ b/Libs/sound/types.h
@@ -2,7 +2,7 @@
 #define SOUND_TYPES_H
 #include <stddef.h>
 #include <stdint.h>
-#include <Mmreg.h>
+#include <mmreg.h>
 #include <j3dcore/j3d.h>
 #include <rdroid/types.h>
 
diff --git a/Libs/std/General/Tests/stdPlatformTest.c b/Libs/std/General/Tests/stdPlatformTest.c
index 8493ca1fc..6d6d28a8d 100644
--- a/Libs/std/General/Tests/stdPlatformTest.c
+++ b/Libs/std/General/Tests/stdPlatformTest.c
@@ -1,5 +1,5 @@
-#include <Windows.h>
-#include <DbgHelp.h>
+#include <windows.h>
+#include <dbghelp.h>
 #include <unity_fixture.h>
 
 #include <stdint.h>
diff --git a/Libs/std/General/std.c b/Libs/std/General/std.c
index 9ce53f1cf..fdd848fbb 100644
--- a/Libs/std/General/std.c
+++ b/Libs/std/General/std.c
@@ -76,7 +76,11 @@ void J3DAPI stdStartup(tHostServices* pHS)
         // TODO: Remove when all round and rand float functions are replaced && updated
         // TODO: consider setting FE_DOWNWARD for round functions (lrintf); i.e.: fesetround(FE_DOWNWARD) to mimic same behavior as OG
         short  tmp = 0;
+#ifdef _MSC_VER
         __asm  fnstcw word ptr[tmp];
+#else
+        __asm__ __volatile__("fnstcw %0" : "=m"(tmp)); // Altered: GCC/MinGW inline assembler syntax for the same instruction
+#endif
         word_183962C = tmp;
 
         // The following flags control in binary (Indy3D.exe) FPU rounding control flags for frndint (floorf, ceilf) and fistp (lrintf)
diff --git a/Libs/std/General/stdColor.h b/Libs/std/General/stdColor.h
index f8d0f3a0b..059cfad54 100644
--- a/Libs/std/General/stdColor.h
+++ b/Libs/std/General/stdColor.h
@@ -300,7 +300,7 @@ void stdColor_DecodeRGBA(uint32_t encoded, const ColorInfo* ci, uint8_t* r, uint
 uint32_t stdColor_Recode(uint32_t encoded, const ColorInfo* pSrcCI, const ColorInfo* pDestCI); // Added
 
 // Added
-inline void stdColor_CalcColorBits(uint32_t bitmask, uint32_t* cbpp, int32_t* posShift, int32_t* posShiftRight)
+static inline void stdColor_CalcColorBits(uint32_t bitmask, uint32_t* cbpp, int32_t* posShift, int32_t* posShiftRight)
 {
     if ( !cbpp || !posShift || !posShiftRight )
     {
diff --git a/Libs/std/General/stdConffile.h b/Libs/std/General/stdConffile.h
index 2cb338b40..beb1e2295 100644
--- a/Libs/std/General/stdConffile.h
+++ b/Libs/std/General/stdConffile.h
@@ -50,7 +50,7 @@ int J3DAPI stdConffile_Read(void* pData, size_t size);
 int J3DAPI stdConffile_ReadArgsFromStr(char* pStr);
 int stdConffile_ReadArgs(void);
 int stdConffile_ReadLine(void);
-int stdConffile_ScanLine(const char* pFormat, ...); // Added
+static inline int stdConffile_ScanLine(const char* pFormat, ...); // Added
 
 tFileHandle stdConffile_GetFileHandle(void);
 tFileHandle stdConffile_GetWriteFileHandle(void); // Added
@@ -79,7 +79,7 @@ void stdConffile_ResetGlobals(void);
  *       a pointer to the data and the size of the receiving buffer (as an `rsize_t` type),
  *       where the size may be 1 when using `%c` to read a single character.
  */
-inline int stdConffile_ScanLine(const char* pFormat, ...)
+static inline int stdConffile_ScanLine(const char* pFormat, ...)
 {
     if ( !stdConffile_ReadLine() )
     {
diff --git a/Libs/std/General/stdHashtbl.c b/Libs/std/General/stdHashtbl.c
index e6f7eed19..4103b381d 100644
--- a/Libs/std/General/stdHashtbl.c
+++ b/Libs/std/General/stdHashtbl.c
@@ -1,6 +1,6 @@
 #include "std.h"
 #include "stdHashtbl.h"
-#include "stdLinklist.h"
+#include "stdLinkList.h"
 #include "stdMemory.h"
 #include "stdUtil.h"
 
diff --git a/Libs/std/General/stdPlatform.c b/Libs/std/General/stdPlatform.c
index b3c58bb28..2cb906073 100644
--- a/Libs/std/General/stdPlatform.c
+++ b/Libs/std/General/stdPlatform.c
@@ -1,6 +1,6 @@
 
 #define STRICT
-#include <Windows.h> // timeGetTime, include first to avoid undefined warning due to WIN32_LEAN_AND_MEAN
+#include <windows.h> // timeGetTime, include first to avoid undefined warning due to WIN32_LEAN_AND_MEAN
 #include <dbghelp.h>
 #include <wchar.h>
 
diff --git a/Libs/std/General/stdUtil.h b/Libs/std/General/stdUtil.h
index 911066303..89facafc5 100644
--- a/Libs/std/General/stdUtil.h
+++ b/Libs/std/General/stdUtil.h
@@ -261,7 +261,7 @@ uint32_t J3DAPI stdUtil_CalcChecksum(const uint8_t* pData, size_t dataSize, uint
  *
  * @return `true` on success, otherwise `false`.
  */
-inline bool J3DAPI stdUtil_StringCopy(char* pDest, size_t destSize, const char* pSrc)
+static inline bool J3DAPI stdUtil_StringCopy(char* pDest, size_t destSize, const char* pSrc)
 {
     // Added: Release-build guard before calculating destSize - 1.
     STD_GUARD(pDest && pSrc && destSize, false);
@@ -282,7 +282,7 @@ inline bool J3DAPI stdUtil_StringCopy(char* pDest, size_t destSize, const char*
  *
  * @return `true` on success, otherwise `false`.
  */
-inline bool J3DAPI stdUtil_WStringCopy(wchar_t* pDest, size_t destSize, const wchar_t* pSrc)
+static inline bool J3DAPI stdUtil_WStringCopy(wchar_t* pDest, size_t destSize, const wchar_t* pSrc)
 {
     // Added: Release-build guard before calculating destSize - 1.
     STD_GUARD(pDest && pSrc && destSize, false);
@@ -304,7 +304,7 @@ inline bool J3DAPI stdUtil_WStringCopy(wchar_t* pDest, size_t destSize, const wc
  *
  * @return `true` on success, otherwise `false`.
  */
-inline bool J3DAPI stdUtil_StringNumCopy(char* pDest, size_t destSize, const char* pSrc, size_t num)
+static inline bool J3DAPI stdUtil_StringNumCopy(char* pDest, size_t destSize, const char* pSrc, size_t num)
 {
     // Added: Release-build guard before calculating destSize - 1.
     STD_GUARD(pDest && pSrc && destSize, false);
@@ -327,7 +327,7 @@ inline bool J3DAPI stdUtil_StringNumCopy(char* pDest, size_t destSize, const cha
  *
  * @return `true` on success, otherwise `false`.
  */
-inline bool J3DAPI stdUtil_WStringNumCopy(wchar_t* pDest, size_t destSize, const wchar_t* pSrc, size_t num)
+static inline bool J3DAPI stdUtil_WStringNumCopy(wchar_t* pDest, size_t destSize, const wchar_t* pSrc, size_t num)
 {
     // Added: Release-build guard before calculating destSize - 1.
     STD_GUARD(pDest && pSrc && destSize, false);
@@ -348,7 +348,7 @@ inline bool J3DAPI stdUtil_WStringNumCopy(wchar_t* pDest, size_t destSize, const
  *
  * @return `true` on success, otherwise `false`.
  */
-inline bool J3DAPI stdUtil_StringCat(char* pDst, size_t destSize, const char* pSrc)
+static inline bool J3DAPI stdUtil_StringCat(char* pDst, size_t destSize, const char* pSrc)
 {
     // Added: Release-build guard before calculating remaining capacity.
     STD_GUARD(pDst && pSrc && destSize, false);
@@ -375,7 +375,7 @@ inline bool J3DAPI stdUtil_StringCat(char* pDst, size_t destSize, const char* pS
  *
  * @return `true` on success, otherwise `false`.
  */
-inline bool J3DAPI stdUtil_StringNumCat(char* pDst, size_t destSize, const char* pSrc, size_t num)
+static inline bool J3DAPI stdUtil_StringNumCat(char* pDst, size_t destSize, const char* pSrc, size_t num)
 {
     // Added: Release-build guard before calculating remaining capacity.
     STD_GUARD(pDst && pSrc && destSize, false);
diff --git a/Libs/std/Win95/DX9/Shaders/common.hlsli b/Libs/std/Win95/DX9/Shaders/common.hlsli
index 96584bff5..13cfaa329 100644
--- a/Libs/std/Win95/DX9/Shaders/common.hlsli
+++ b/Libs/std/Win95/DX9/Shaders/common.hlsli
@@ -1,7 +1,8 @@
 #ifndef J3D_COMMON_HLSL
 #define J3D_COMMON_HLSL
 
-#define MERGE_TOKENS(a, b) a##b
+#define MERGE_TOKENS_(a, b) a##b
+#define MERGE_TOKENS(a, b) MERGE_TOKENS_(a, b)
 
 // ===== VERTEX SHADER CONSTANTS (c24-c255) =====
 #define VS_VIEWPORT_REGISTER c0
diff --git a/Libs/std/Win95/DX9/stdControlDX9.c b/Libs/std/Win95/DX9/stdControlDX9.c
index 44357a1b7..fb4b877e3 100644
--- a/Libs/std/Win95/DX9/stdControlDX9.c
+++ b/Libs/std/Win95/DX9/stdControlDX9.c
@@ -8,7 +8,7 @@
 #include <std/General/stdUtil.h>
 #include <std/RTI/symbols.h>
 
-#include <Xinput.h>
+#include <xinput.h>
 #pragma comment(lib,"Xinput.lib")
 
 #include <wbemidl.h>
diff --git a/Libs/std/Win95/DX9/stdShaderDX9.c b/Libs/std/Win95/DX9/stdShaderDX9.c
index 2a240aa9d..6a21d2318 100644
--- a/Libs/std/Win95/DX9/stdShaderDX9.c
+++ b/Libs/std/Win95/DX9/stdShaderDX9.c
@@ -7,7 +7,7 @@
 #include <std/Win95/std3D.h>
 
 #include <d3d9.h>
-#include <D3Dcommon.h>
+#include <d3dcommon.h>
 #include <d3dcompiler.h>
 #pragma comment(lib,"d3dcompiler.lib")
 
diff --git a/Libs/std/Win95/stdControl.h b/Libs/std/Win95/stdControl.h
index 3bec4d5c3..b8e2e6275 100644
--- a/Libs/std/Win95/stdControl.h
+++ b/Libs/std/Win95/stdControl.h
@@ -12,7 +12,7 @@
 #  endif
 #include <dinput.h>
 #  if defined(J3D_TEST)
-#       include <Xinput.h>
+#       include <xinput.h>
 #  endif
 #endif
 
diff --git a/Libs/std/Win95/stdGob.c b/Libs/std/Win95/stdGob.c
index 2ffc51cc3..c78321320 100644
--- a/Libs/std/Win95/stdGob.c
+++ b/Libs/std/Win95/stdGob.c
@@ -1,7 +1,7 @@
 #include "stdGob.h"
 #include <j3dcore/j3dhook.h>
 #include <std/General/std.h>
-#include <std/General/stdHashTbl.h>
+#include <std/General/stdHashtbl.h>
 #include <std/General/stdMemory.h>
 #include <std/General/stdUtil.h>
 #include <std/RTI/symbols.h>
diff --git a/Libs/w32util/wuRegistry.h b/Libs/w32util/wuRegistry.h
index 94f455674..d6d89a04b 100644
--- a/Libs/w32util/wuRegistry.h
+++ b/Libs/w32util/wuRegistry.h
@@ -1,7 +1,7 @@
 #ifndef W32UTIL_WUREGISTRY_H
 #define W32UTIL_WUREGISTRY_H
 #define STRICT
-#include <Windows.h>
+#include <windows.h>
 #include <j3dcore/j3d.h>
 #include <w32util/RTI/addresses.h>
 
diff --git a/Libs/wkernel/wkernel.c b/Libs/wkernel/wkernel.c
index f88058e96..c513c8844 100644
--- a/Libs/wkernel/wkernel.c
+++ b/Libs/wkernel/wkernel.c
@@ -4,7 +4,7 @@
 #include <j3dcore/j3dhook.h>
 #include <std/Win95/stdWin95.h>
 
-#include <CommCtrl.h> // InitCommonControls
+#include <commctrl.h> // InitCommonControls
 #include <initguid.h> // DEFINE_GUID
 
 
diff --git a/Programs/byacc/main.c b/Programs/byacc/main.c
index 2eb80b84f..1d6deab10 100644
--- a/Programs/byacc/main.c
+++ b/Programs/byacc/main.c
@@ -1,5 +1,5 @@
 #ifdef _WIN32
-#include <Windows.h>
+#include <windows.h>
 #else
 #include <unistd.h>
 #endif
diff --git a/Programs/flex/main.c b/Programs/flex/main.c
index b41718905..7698522e2 100644
--- a/Programs/flex/main.c
+++ b/Programs/flex/main.c
@@ -38,7 +38,7 @@ static char rcsid[] =
 #endif
 
 #ifdef _WIN32
-#include <Windows.h>
+#include <windows.h>
 #endif
 
 #include "flexdef.h"