diff --git a/reactos/win32ss/drivers/miniport/vga/initvga.c b/reactos/win32ss/drivers/miniport/vga/initvga.c
index 8834513a98c..5e9c4b6dd95 100644
--- a/reactos/win32ss/drivers/miniport/vga/initvga.c
+++ b/reactos/win32ss/drivers/miniport/vga/initvga.c
@@ -107,7 +107,7 @@ vgaSetRegisters(PVGA_REGISTERS Registers)
 }
 
 VOID
-InitVGAMode()
+InitVGAMode(VOID)
 {
    vgaSaveRegisters(&TextModeRegs);
    vgaSetRegisters(&Mode12Regs);
diff --git a/reactos/win32ss/gdi/eng/pdevobj.c b/reactos/win32ss/gdi/eng/pdevobj.c
index 214537a780b..6645f1d6120 100644
--- a/reactos/win32ss/gdi/eng/pdevobj.c
+++ b/reactos/win32ss/gdi/eng/pdevobj.c
@@ -18,7 +18,7 @@ static HSEMAPHORE ghsemPDEV;
 INIT_FUNCTION
 NTSTATUS
 NTAPI
-InitPDEVImpl()
+InitPDEVImpl(VOID)
 {
     ghsemPDEV = EngCreateSemaphore();
     if (!ghsemPDEV) return STATUS_INSUFFICIENT_RESOURCES;
@@ -50,7 +50,7 @@ DbgLookupDHPDEV(DHPDEV dhpdev)
 #endif
 
 PPDEVOBJ
-PDEVOBJ_AllocPDEV()
+PDEVOBJ_AllocPDEV(VOID)
 {
     PPDEVOBJ ppdev;
 
diff --git a/reactos/win32ss/gdi/eng/stubs.c b/reactos/win32ss/gdi/eng/stubs.c
index b4e8c51f4f0..6285c9d34b7 100644
--- a/reactos/win32ss/gdi/eng/stubs.c
+++ b/reactos/win32ss/gdi/eng/stubs.c
@@ -669,7 +669,7 @@ EngHangNotification(
  */
 BOOL
 APIENTRY
-EngLpkInstalled()
+EngLpkInstalled(VOID)
 {
     UNIMPLEMENTED;
     return FALSE;
@@ -803,7 +803,7 @@ HT_Get8BPPMaskPalette(
  */
 BOOL
 APIENTRY
-NtGdiAnyLinkedFonts()
+NtGdiAnyLinkedFonts(VOID)
 {
     UNIMPLEMENTED;
     return FALSE;
diff --git a/reactos/win32ss/gdi/gdi32/misc/gdientry.c b/reactos/win32ss/gdi/gdi32/misc/gdientry.c
index eb933dff41a..9b8a4a3c815 100644
--- a/reactos/win32ss/gdi/gdi32/misc/gdientry.c
+++ b/reactos/win32ss/gdi/gdi32/misc/gdientry.c
@@ -2028,7 +2028,7 @@ DdUnattachSurface(LPDDRAWI_DDRAWSURFACE_LCL pSurface,
  */
 ULONG
 WINAPI
-DdQueryDisplaySettingsUniqueness()
+DdQueryDisplaySettingsUniqueness(VOID)
 {
     return GdiSharedHandleTable->flDeviceUniq;
 }
diff --git a/reactos/win32ss/gdi/gdi32/misc/misc.c b/reactos/win32ss/gdi/gdi32/misc/misc.c
index f53651041a1..296166fd77b 100644
--- a/reactos/win32ss/gdi/gdi32/misc/misc.c
+++ b/reactos/win32ss/gdi/gdi32/misc/misc.c
@@ -41,7 +41,7 @@ extern PGDIHANDLECACHE GdiHandleCache;
  */
 BOOL
 WINAPI
-GdiFlush()
+GdiFlush(VOID)
 {
     NtGdiFlush();
     return TRUE;
@@ -459,7 +459,7 @@ GdiSetBatchLimit(DWORD	Limit)
  */
 DWORD
 WINAPI
-GdiGetBatchLimit()
+GdiGetBatchLimit(VOID)
 {
     return GDI_BatchLimit;
 }
diff --git a/reactos/win32ss/gdi/ntgdi/dclife.c b/reactos/win32ss/gdi/ntgdi/dclife.c
index 066cf30fc28..22390b812d5 100644
--- a/reactos/win32ss/gdi/ntgdi/dclife.c
+++ b/reactos/win32ss/gdi/ntgdi/dclife.c
@@ -50,7 +50,7 @@ static const MATRIX	gmxWorldToPageDefault =
 INIT_FUNCTION
 NTSTATUS
 NTAPI
-InitDcImpl()
+InitDcImpl(VOID)
 {
     psurfDefaultBitmap = SURFACE_ShareLockSurface(StockObjects[DEFAULT_BITMAP]);
     if (!psurfDefaultBitmap)
diff --git a/reactos/win32ss/gdi/ntgdi/gdidbg.c b/reactos/win32ss/gdi/ntgdi/gdidbg.c
index 33661e9bc38..d9227f124cf 100644
--- a/reactos/win32ss/gdi/ntgdi/gdidbg.c
+++ b/reactos/win32ss/gdi/ntgdi/gdidbg.c
@@ -20,7 +20,7 @@ extern PENTRY gpentHmgr;;
 ULONG gulLogUnique = 0;
 
 /* Note: the following values need to be sorted */
-DBG_CHANNEL DbgChannels[DbgChCount]={
+DBG_CHANNEL DbgChannels[DbgChCount] = {
     {L"EngBlt", DbgChEngBlt},
     {L"EngBrush", DbgChEngBrush},
     {L"EngClip", DbgChEngClip},
@@ -281,7 +281,7 @@ DbgDumpGdiHandleTableWithBT(void)
 
 BOOL
 NTAPI
-DbgGdiHTIntegrityCheck()
+DbgGdiHTIntegrityCheck(VOID)
 {
 	ULONG i, nDeleted = 0, nFree = 0, nUsed = 0;
 	PGDI_TABLE_ENTRY pEntry;
@@ -516,7 +516,7 @@ DbgCleanupEventList(PSLIST_HEADER pslh)
 
 VOID
 NTAPI
-DbgDumpLockedGdiHandles()
+DbgDumpLockedGdiHandles(VOID)
 {
     ULONG i;
 
@@ -733,7 +733,7 @@ DbgParseDebugChannels(PPROCESSINFO ppi, PUNICODE_STRING Value)
     return TRUE;
 }
 
-BOOL DbgInitDebugChannels()
+BOOL DbgInitDebugChannels(VOID)
 {
     WCHAR valBuffer[100];
     UNICODE_STRING Value;
diff --git a/reactos/win32ss/gdi/ntgdi/palette.c b/reactos/win32ss/gdi/ntgdi/palette.c
index 92e5872836c..0bf7f69ccbd 100644
--- a/reactos/win32ss/gdi/ntgdi/palette.c
+++ b/reactos/win32ss/gdi/ntgdi/palette.c
@@ -60,7 +60,7 @@ unsigned short GetNumberOfBits(unsigned int dwMask)
 INIT_FUNCTION
 NTSTATUS
 NTAPI
-InitPaletteImpl()
+InitPaletteImpl(VOID)
 {
     // Create default palette (20 system colors)
     gppalDefault = PALETTE_AllocPalWithHandle(PAL_INDEXED,
diff --git a/reactos/win32ss/reactx/dxapi/main.c b/reactos/win32ss/reactx/dxapi/main.c
index b50f3c74c53..58443ad2a51 100644
--- a/reactos/win32ss/reactx/dxapi/main.c
+++ b/reactos/win32ss/reactx/dxapi/main.c
@@ -41,7 +41,7 @@ DriverEntry(IN PVOID Context1,
 *--*/
 ULONG
 NTAPI
-DxApiGetVersion()
+DxApiGetVersion(VOID)
 {
     /* MSDN say this always return Direct Sound version 4.02 */
     return 0x402;
diff --git a/reactos/win32ss/reactx/ntddraw/dxeng.c b/reactos/win32ss/reactx/ntddraw/dxeng.c
index 3ad931653cb..b427938f88a 100644
--- a/reactos/win32ss/reactx/ntddraw/dxeng.c
+++ b/reactos/win32ss/reactx/ntddraw/dxeng.c
@@ -12,7 +12,7 @@
 HSEMAPHORE  ghsemShareDevLock = NULL;
 
 ULONG gcEngFuncs = DXENG_INDEX_DxEngLoadImage + 1;
-DRVFN gaEngFuncs [] =
+DRVFN gaEngFuncs[] =
 {
     {0, (PFN) NULL},
     {DXENG_INDEX_DxEngNUIsTermSrv, (PFN)DxEngNUIsTermSrv},
@@ -75,7 +75,7 @@ DRVFN gaEngFuncs [] =
 *--*/
 ULONG
 APIENTRY
-DxEngDispUniq()
+DxEngDispUniq(VOID)
 {
     DPRINT1("ReactX Calling : DxEngDispUniq\n");
     return GdiHandleTable->flDeviceUniq;
@@ -176,7 +176,7 @@ DxEngUnlockDC(PDC pDC)
 *--*/
 BOOLEAN
 APIENTRY
-DxEngLockShareSem()
+DxEngLockShareSem(VOID)
 {
     DPRINT1("ReactX Calling : DxEngLockShareSem\n");
     if(!ghsemShareDevLock) ghsemShareDevLock = EngCreateSemaphore(); // Hax, should be in dllmain.c
@@ -199,7 +199,7 @@ DxEngLockShareSem()
 *--*/
 BOOLEAN
 APIENTRY
-DxEngUnlockShareSem()
+DxEngUnlockShareSem(VOID)
 {
     DPRINT1("ReactX Calling : DxEngUnlockShareSem\n");
     EngReleaseSemaphore(ghsemShareDevLock);
@@ -498,7 +498,7 @@ DxEngGetDCState(HDC hDC,
 *--*/
 BOOLEAN
 APIENTRY
-DxEngIncDispUniq()
+DxEngIncDispUniq(VOID)
 {
     DPRINT1("ReactX Calling : DxEngIncDispUniq \n");
 
@@ -596,7 +596,7 @@ DxEngReferenceHdev(HDEV hDev)
 /* Notes: Check if terminal server got connections or not */
 BOOLEAN
 APIENTRY
-DxEngNUIsTermSrv()
+DxEngNUIsTermSrv(VOID)
 {
     /* FIXME: ReactOS does not suport terminal server yet, we can not check if we got connections or not */
     UNIMPLEMENTED;
@@ -611,7 +611,7 @@ DxEngNUIsTermSrv()
    (redraws current desktop) */
 BOOLEAN
 APIENTRY
-DxEngRedrawDesktop()
+DxEngRedrawDesktop(VOID)
 {
     UserRedrawDesktop();
     return TRUE;
@@ -626,7 +626,7 @@ ULONG gulVisRgnUniqueness; // Increase count everytime client region is updated.
 /* Notes: returns the VisRgnUniq counter for win32k */
 ULONG
 APIENTRY
-DxEngVisRgnUniq()
+DxEngVisRgnUniq(VOID)
 {
     DPRINT1("ReactX Calling : DxEngVisRgnUniq \n");
 
@@ -659,7 +659,7 @@ DxEngCreateMemoryDC(HDEV hDev)
 /************************************************************************/
 /* DxEngScreenAccessCheck                                               */
 /************************************************************************/
-DWORD APIENTRY DxEngScreenAccessCheck()
+DWORD APIENTRY DxEngScreenAccessCheck(VOID)
 {
     UNIMPLEMENTED;
 
diff --git a/reactos/win32ss/user/ntuser/callback.c b/reactos/win32ss/user/ntuser/callback.c
index fbad4a2fd2f..e1d6024e8cd 100644
--- a/reactos/win32ss/user/ntuser/callback.c
+++ b/reactos/win32ss/user/ntuser/callback.c
@@ -424,7 +424,7 @@ co_IntCallWindowProc(WNDPROC Proc,
 }
 
 HMENU APIENTRY
-co_IntLoadSysMenuTemplate()
+co_IntLoadSysMenuTemplate(VOID)
 {
    LRESULT Result = 0;
    NTSTATUS Status;
diff --git a/reactos/win32ss/user/ntuser/cursoricon.c b/reactos/win32ss/user/ntuser/cursoricon.c
index 574d229f3ba..11267afb1e5 100644
--- a/reactos/win32ss/user/ntuser/cursoricon.c
+++ b/reactos/win32ss/user/ntuser/cursoricon.c
@@ -184,7 +184,7 @@ IntLoadSystenIcons(HICON hcur, DWORD id)
 }
 
 PSYSTEM_CURSORINFO
-IntGetSysCursorInfo()
+IntGetSysCursorInfo(VOID)
 {
     return &gSysCursorInfo;
 }
diff --git a/reactos/win32ss/user/ntuser/desktop.c b/reactos/win32ss/user/ntuser/desktop.c
index 5cff709cb1d..7cd27d6691f 100644
--- a/reactos/win32ss/user/ntuser/desktop.c
+++ b/reactos/win32ss/user/ntuser/desktop.c
@@ -723,7 +723,7 @@ UserMessageWindowProc(PWND pwnd, UINT Msg, WPARAM wParam, LPARAM lParam, LRESULT
     return TRUE; /* We are done. Do not do any callbacks to user mode */
 }
 
-VOID NTAPI DesktopThreadMain()
+VOID NTAPI DesktopThreadMain(VOID)
 {
     BOOL Ret;
     MSG Msg;
@@ -769,7 +769,7 @@ UserGetDesktopDC(ULONG DcType, BOOL EmptyDC, BOOL ValidatehWnd)
 }
 
 VOID APIENTRY
-UserRedrawDesktop()
+UserRedrawDesktop(VOID)
 {
     PWND Window = NULL;
     PREGION Rgn;
diff --git a/reactos/win32ss/user/ntuser/display.c b/reactos/win32ss/user/ntuser/display.c
index dbd45102307..8901c018003 100644
--- a/reactos/win32ss/user/ntuser/display.c
+++ b/reactos/win32ss/user/ntuser/display.c
@@ -152,7 +152,7 @@ InitDisplayDriver(
 
 NTSTATUS
 NTAPI
-InitVideo()
+InitVideo(VOID)
 {
     ULONG iDevNum, iVGACompatible = -1, ulMaxObjectNumber = 0;
     WCHAR awcDeviceName[20];
diff --git a/reactos/win32ss/user/ntuser/input.c b/reactos/win32ss/user/ntuser/input.c
index aac846a8e9c..fd7207eb26f 100644
--- a/reactos/win32ss/user/ntuser/input.c
+++ b/reactos/win32ss/user/ntuser/input.c
@@ -125,7 +125,7 @@ OpenInputDevice(PHANDLE pHandle, PFILE_OBJECT *ppObject, CONST WCHAR *pszDeviceN
  * Reads data from input devices and supports win32 timers
  */
 VOID NTAPI
-RawInputThreadMain()
+RawInputThreadMain(VOID)
 {
     NTSTATUS MouStatus = STATUS_UNSUCCESSFUL, KbdStatus = STATUS_UNSUCCESSFUL, Status;
     IO_STATUS_BLOCK MouIosb, KbdIosb;
diff --git a/reactos/win32ss/user/ntuser/message.c b/reactos/win32ss/user/ntuser/message.c
index 262ca9db528..cc651e2063a 100644
--- a/reactos/win32ss/user/ntuser/message.c
+++ b/reactos/win32ss/user/ntuser/message.c
@@ -1937,7 +1937,7 @@ IntGetQueueStatus(DWORD Changes)
 }
 
 BOOL APIENTRY
-IntInitMessagePumpHook()
+IntInitMessagePumpHook(VOID)
 {
     PTHREADINFO pti = PsGetCurrentThreadWin32Thread();
 
@@ -1950,7 +1950,7 @@ IntInitMessagePumpHook()
 }
 
 BOOL APIENTRY
-IntUninitMessagePumpHook()
+IntUninitMessagePumpHook(VOID)
 {
     PTHREADINFO pti = PsGetCurrentThreadWin32Thread();
 
diff --git a/reactos/win32ss/user/ntuser/monitor.c b/reactos/win32ss/user/ntuser/monitor.c
index 45deea9d91a..256658171bd 100644
--- a/reactos/win32ss/user/ntuser/monitor.c
+++ b/reactos/win32ss/user/ntuser/monitor.c
@@ -30,7 +30,7 @@ static PMONITOR gMonitorList = NULL;
  */
 static
 PMONITOR
-IntCreateMonitorObject()
+IntCreateMonitorObject(VOID)
 {
     return UserCreateObject(gHandleTable, NULL, NULL, NULL, TYPE_MONITOR, sizeof(MONITOR));
 }
@@ -99,7 +99,7 @@ UserGetMonitorObject(IN HMONITOR hMonitor)
  *   PMONITOR
  */
 PMONITOR NTAPI
-UserGetPrimaryMonitor()
+UserGetPrimaryMonitor(VOID)
 {
     PMONITOR pMonitor;
 
diff --git a/reactos/win32ss/user/ntuser/object.c b/reactos/win32ss/user/ntuser/object.c
index 72e55eff4aa..72a2b7fcd4a 100644
--- a/reactos/win32ss/user/ntuser/object.c
+++ b/reactos/win32ss/user/ntuser/object.c
@@ -246,7 +246,7 @@ static const struct
 
 #if DBG
 
-void DbgUserDumpHandleTable()
+void DbgUserDumpHandleTable(VOID)
 {
     int HandleCounts[TYPE_CTYPES];
     PPROCESSINFO ppiList;
diff --git a/reactos/win32ss/user/ntuser/sysparams.c b/reactos/win32ss/user/ntuser/sysparams.c
index df43133b92b..2a4baf0d5b3 100644
--- a/reactos/win32ss/user/ntuser/sysparams.c
+++ b/reactos/win32ss/user/ntuser/sysparams.c
@@ -186,7 +186,7 @@ SpiLoadFont(PLOGFONTW plfOut, LPWSTR pwszValueName, PLOGFONTW plfDefault)
 
 static
 VOID
-SpiFixupValues()
+SpiFixupValues(VOID)
 {
     /* Fixup values */
     gspv.ncm.iCaptionWidth = max(gspv.ncm.iCaptionWidth, 8);
@@ -210,7 +210,7 @@ SpiFixupValues()
 
 static
 VOID
-SpiUpdatePerUserSystemParameters()
+SpiUpdatePerUserSystemParameters(VOID)
 {
     static LOGFONTW lf1 = {-11, 0, 0, 0, FW_NORMAL, FALSE, FALSE,
                            FALSE, ANSI_CHARSET, 0, 0, DEFAULT_QUALITY,
@@ -320,7 +320,7 @@ SpiUpdatePerUserSystemParameters()
 }
 
 BOOL
-InitSysParams()
+InitSysParams(VOID)
 {
     SpiUpdatePerUserSystemParameters();
     gbSpiInitialized = TRUE;
@@ -724,7 +724,7 @@ SpiSetWallpaper(PVOID pvParam, FLONG fl)
 }
 
 static BOOL
-SpiNotifyNCMetricsChanged()
+SpiNotifyNCMetricsChanged(VOID)
 {
     PWND pwndDesktop, pwndCurrent;
     HWND *ahwnd;
diff --git a/reactos/win32ss/user/ntuser/winsta.c b/reactos/win32ss/user/ntuser/winsta.c
index 76ffa6d988f..0f757d52cd9 100644
--- a/reactos/win32ss/user/ntuser/winsta.c
+++ b/reactos/win32ss/user/ntuser/winsta.c
@@ -45,7 +45,7 @@ InitWindowStationImpl(VOID)
 
 NTSTATUS
 NTAPI
-UserCreateWinstaDirectory()
+UserCreateWinstaDirectory(VOID)
 {
     PPEB Peb;
     NTSTATUS Status;
diff --git a/reactos/win32ss/user/user32/controls/appswitch.c b/reactos/win32ss/user/user32/controls/appswitch.c
index c7878f546c7..6867194f74c 100644
--- a/reactos/win32ss/user/user32/controls/appswitch.c
+++ b/reactos/win32ss/user/user32/controls/appswitch.c
@@ -54,7 +54,7 @@ void MakeWindowActive(HWND hwnd)
 
    wpl.length = sizeof(WINDOWPLACEMENT);
    GetWindowPlacement(hwnd, &wpl);
-  
+
    TRACE("GetWindowPlacement wpl.showCmd %d\n",wpl.showCmd);
    if (wpl.showCmd == SW_SHOWMINIMIZED)
       ShowWindowAsync(hwnd, SW_RESTORE);
@@ -82,7 +82,7 @@ void CompleteSwitch(BOOL doSwitch)
       //if(selectedWindow != 0)
       {
          HWND hwnd = windowList[selectedWindow];
-                  
+
          GetWindowTextW(hwnd, windowText, _countof(windowText));
 
          TRACE("[ATbot] CompleteSwitch Switching to 0x%08x (%ls)\n", hwnd, windowText);
@@ -107,7 +107,7 @@ BOOL CALLBACK EnumerateCallback(HWND window, LPARAM lParam)
    if ((wcscmp(L"Shell_TrayWnd", windowText)==0) ||
        (wcscmp(L"Progman", windowText)==0) )
             return TRUE;
-      
+
    // First try to get the big icon assigned to the window
    hIcon = (HICON)SendMessageW(window, WM_GETICON, ICON_BIG, 0);
    if (!hIcon)
@@ -161,8 +161,8 @@ void EnumWindowsZOrder(WNDENUMPROC callback, LPARAM lParam)
 
 void ProcessMouseMessage(UINT message, LPARAM lParam)
 {
-   int xPos = LOWORD(lParam); 
-   int yPos = HIWORD(lParam); 
+   int xPos = LOWORD(lParam);
+   int yPos = HIWORD(lParam);
 
    int xIndex = (xPos - xOffset)/40;
    int xOff   = (xPos - xOffset)%40;
@@ -209,7 +209,7 @@ void OnPaint(HWND hWnd)
       for(i=0; i< windowCount; i++)
       {
          HICON hIcon = iconList[i];
-         
+
          int xpos = xOffset + 40 * (i % nCols);
          int ypos = yOffset + 40 * (i / nCols);
 
@@ -266,12 +266,12 @@ DWORD CreateSwitcherWindow(HINSTANCE hInstance)
        TRACE("[ATbot] Task Switcher Window failed to create.\n");
        return 0;
     }
-                                
+
     isOpen = FALSE;
     return 1;
 }
-                                        
-DWORD GetDialogFont()
+
+DWORD GetDialogFont(VOID)
 {
    HDC tDC;
    TEXTMETRIC tm;
@@ -286,11 +286,11 @@ DWORD GetDialogFont()
    return 1;
 }
 
-void PrepareWindow()
+void PrepareWindow(VOID)
 {
    cxBorder = GetSystemMetrics(SM_CXBORDER);
    cyBorder = GetSystemMetrics(SM_CYBORDER);
-   
+
    nItems = windowCount;
    nCols = min(max(nItems,8),12);
    nRows = (nItems+nCols-1)/nCols;
@@ -312,7 +312,7 @@ void PrepareWindow()
    ResizeAndCenter(switchdialog, totalW, totalH);
 }
 
-void ProcessHotKey()
+void ProcessHotKey(VOID)
 {
    if (!isOpen)
    {
@@ -492,7 +492,7 @@ Exit:
 }
 
 VOID
-DestroyAppWindows()
+DestroyAppWindows(VOID)
 {
    INT i;
    for (i=0; i< windowCount; i++)
@@ -516,7 +516,7 @@ LRESULT WINAPI SwitchWndProc_common(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM
       {
          NtUserSetWindowFNID(hWnd, FNID_SWITCH);
       }
-   }    
+   }
 
    switch (uMsg)
    {
diff --git a/reactos/win32ss/user/user32/misc/dllmain.c b/reactos/win32ss/user/user32/misc/dllmain.c
index 3f764a9b3b4..65466291658 100644
--- a/reactos/win32ss/user/user32/misc/dllmain.c
+++ b/reactos/win32ss/user/user32/misc/dllmain.c
@@ -24,7 +24,7 @@ HICON hIconSmWindows = NULL, hIconWindows = NULL;
 WCHAR szAppInit[KEY_LENGTH];
 
 BOOL
-GetDllList()
+GetDllList(VOID)
 {
     NTSTATUS Status;
     OBJECT_ATTRIBUTES Attributes;
@@ -123,7 +123,7 @@ end:
 
 
 VOID
-LoadAppInitDlls()
+LoadAppInitDlls(VOID)
 {
     szAppInit[0] = UNICODE_NULL;
 
@@ -156,7 +156,7 @@ LoadAppInitDlls()
 }
 
 VOID
-UnloadAppInitDlls()
+UnloadAppInitDlls(VOID)
 {
     if (szAppInit[0] != UNICODE_NULL)
     {