diff --git a/dlls/comctl32/animate.c b/dlls/comctl32/animate.c
index e873ee2cd01..627e22eec01 100644
--- a/dlls/comctl32/animate.c
+++ b/dlls/comctl32/animate.c
@@ -698,8 +698,6 @@ void ANIMATE_Register(void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA(ANIMATE_CLASSA)) return;
-
     ZeroMemory(&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS | CS_DBLCLKS;
     wndClass.lpfnWndProc   = (WNDPROC)ANIMATE_WindowProc;
@@ -715,7 +713,6 @@ void ANIMATE_Register(void)
 
 void ANIMATE_Unregister(void)
 {
-    if (GlobalFindAtomA(ANIMATE_CLASSA))
-	UnregisterClassA(ANIMATE_CLASSA, (HINSTANCE)NULL);
+    UnregisterClassA(ANIMATE_CLASSA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/comboex.c b/dlls/comctl32/comboex.c
index 0655f7c7fc0..6ff7a32b75c 100644
--- a/dlls/comctl32/comboex.c
+++ b/dlls/comctl32/comboex.c
@@ -311,8 +311,6 @@ COMBOEX_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (WC_COMBOBOXEXA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS;
     wndClass.lpfnWndProc   = (WNDPROC)COMBOEX_WindowProc;
@@ -329,7 +327,6 @@ COMBOEX_Register (void)
 VOID
 COMBOEX_Unregister (void)
 {
-    if (GlobalFindAtomA (WC_COMBOBOXEXA))
-	UnregisterClassA (WC_COMBOBOXEXA, (HINSTANCE)NULL);
+    UnregisterClassA (WC_COMBOBOXEXA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/datetime.c b/dlls/comctl32/datetime.c
index 5bcc6a42e2c..5c5dfd52424 100644
--- a/dlls/comctl32/datetime.c
+++ b/dlls/comctl32/datetime.c
@@ -1104,8 +1104,6 @@ DATETIME_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (DATETIMEPICK_CLASSA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS;
     wndClass.lpfnWndProc   = (WNDPROC)DATETIME_WindowProc;
@@ -1122,7 +1120,6 @@ DATETIME_Register (void)
 VOID
 DATETIME_Unregister (void)
 {
-    if (GlobalFindAtomA (DATETIMEPICK_CLASSA))
-	UnregisterClassA (DATETIMEPICK_CLASSA, (HINSTANCE)NULL);
+    UnregisterClassA (DATETIMEPICK_CLASSA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/flatsb.c b/dlls/comctl32/flatsb.c
index 29af397ed62..1601a441fd7 100644
--- a/dlls/comctl32/flatsb.c
+++ b/dlls/comctl32/flatsb.c
@@ -155,8 +155,6 @@ FLATSB_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (FLATSB_CLASSA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS;
     wndClass.lpfnWndProc   = (WNDPROC)FlatSB_WindowProc;
@@ -173,7 +171,6 @@ FLATSB_Register (void)
 VOID
 FLATSB_Unregister (void)
 {
-    if (GlobalFindAtomA (FLATSB_CLASSA))
-	UnregisterClassA (FLATSB_CLASSA, (HINSTANCE)NULL);
+    UnregisterClassA (FLATSB_CLASSA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/header.c b/dlls/comctl32/header.c
index 545ef069436..6f221e7294b 100644
--- a/dlls/comctl32/header.c
+++ b/dlls/comctl32/header.c
@@ -1555,8 +1555,6 @@ HEADER_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (WC_HEADERA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS | CS_DBLCLKS;
     wndClass.lpfnWndProc   = (WNDPROC)HEADER_WindowProc;
@@ -1572,7 +1570,6 @@ HEADER_Register (void)
 VOID
 HEADER_Unregister (void)
 {
-    if (GlobalFindAtomA (WC_HEADERA))
-	UnregisterClassA (WC_HEADERA, (HINSTANCE)NULL);
+    UnregisterClassA (WC_HEADERA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/hotkey.c b/dlls/comctl32/hotkey.c
index 60c903ead9b..c7dd58c1d18 100644
--- a/dlls/comctl32/hotkey.c
+++ b/dlls/comctl32/hotkey.c
@@ -334,8 +334,6 @@ HOTKEY_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (HOTKEY_CLASSA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS;
     wndClass.lpfnWndProc   = (WNDPROC)HOTKEY_WindowProc;
@@ -352,7 +350,6 @@ HOTKEY_Register (void)
 VOID
 HOTKEY_Unregister (void)
 {
-    if (GlobalFindAtomA (HOTKEY_CLASSA))
-	UnregisterClassA (HOTKEY_CLASSA, (HINSTANCE)NULL);
+    UnregisterClassA (HOTKEY_CLASSA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/ipaddress.c b/dlls/comctl32/ipaddress.c
index 850cd32a831..a0bddb965e8 100644
--- a/dlls/comctl32/ipaddress.c
+++ b/dlls/comctl32/ipaddress.c
@@ -652,8 +652,6 @@ void IPADDRESS_Register (void)
 {
   WNDCLASSA wndClass;
 
-  if (GlobalFindAtomA (WC_IPADDRESSA)) return;
-
   ZeroMemory (&wndClass, sizeof(WNDCLASSA));
   wndClass.style         = CS_GLOBALCLASS;
   wndClass.lpfnWndProc   = (WNDPROC)IPADDRESS_WindowProc;
@@ -669,6 +667,5 @@ void IPADDRESS_Register (void)
 
 VOID IPADDRESS_Unregister (void)
 {
-  if (GlobalFindAtomA (WC_IPADDRESSA))
   UnregisterClassA (WC_IPADDRESSA, (HINSTANCE)NULL);
 }
diff --git a/dlls/comctl32/listview.c b/dlls/comctl32/listview.c
index 279cc6e41df..697d2061203 100644
--- a/dlls/comctl32/listview.c
+++ b/dlls/comctl32/listview.c
@@ -7320,8 +7320,6 @@ VOID LISTVIEW_Register(void)
 {
   WNDCLASSA wndClass;
 
-  if (!GlobalFindAtomA(WC_LISTVIEWA)) 
-  {
     ZeroMemory(&wndClass, sizeof(WNDCLASSA));
     wndClass.style = CS_GLOBALCLASS | CS_DBLCLKS;
     wndClass.lpfnWndProc = (WNDPROC)LISTVIEW_WindowProc;
@@ -7331,7 +7329,6 @@ VOID LISTVIEW_Register(void)
     wndClass.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
     wndClass.lpszClassName = WC_LISTVIEWA;
     RegisterClassA(&wndClass);
-  }
 }
 
 /***
@@ -7346,10 +7343,7 @@ VOID LISTVIEW_Register(void)
  */
 VOID LISTVIEW_Unregister(void)
 {
-  if (GlobalFindAtomA(WC_LISTVIEWA))
-  {
     UnregisterClassA(WC_LISTVIEWA, (HINSTANCE)NULL);
-  }
 }
 
 /***
diff --git a/dlls/comctl32/monthcal.c b/dlls/comctl32/monthcal.c
index 95e71eecece..0cfeb5a7a90 100644
--- a/dlls/comctl32/monthcal.c
+++ b/dlls/comctl32/monthcal.c
@@ -1742,8 +1742,6 @@ MONTHCAL_Register(void)
 {
   WNDCLASSA wndClass;
 
-  if(GlobalFindAtomA(MONTHCAL_CLASSA)) return;
-
   ZeroMemory(&wndClass, sizeof(WNDCLASSA));
   wndClass.style         = CS_GLOBALCLASS;
   wndClass.lpfnWndProc   = (WNDPROC)MONTHCAL_WindowProc;
@@ -1760,6 +1758,5 @@ MONTHCAL_Register(void)
 void
 MONTHCAL_Unregister(void)
 {
-  if(GlobalFindAtomA(MONTHCAL_CLASSA))
     UnregisterClassA(MONTHCAL_CLASSA, (HINSTANCE)NULL);
 }
diff --git a/dlls/comctl32/nativefont.c b/dlls/comctl32/nativefont.c
index 33ee44f62c4..31e73ba5fe6 100644
--- a/dlls/comctl32/nativefont.c
+++ b/dlls/comctl32/nativefont.c
@@ -85,8 +85,6 @@ NATIVEFONT_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (WC_NATIVEFONTCTLA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS;
     wndClass.lpfnWndProc   = (WNDPROC)NATIVEFONT_WindowProc;
@@ -103,7 +101,6 @@ NATIVEFONT_Register (void)
 VOID
 NATIVEFONT_Unregister (void)
 {
-    if (GlobalFindAtomA (WC_NATIVEFONTCTLA))
-	UnregisterClassA (WC_NATIVEFONTCTLA, (HINSTANCE)NULL);
+    UnregisterClassA (WC_NATIVEFONTCTLA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/pager.c b/dlls/comctl32/pager.c
index 44a01e3b0e6..0b299f28a33 100644
--- a/dlls/comctl32/pager.c
+++ b/dlls/comctl32/pager.c
@@ -367,8 +367,6 @@ PAGER_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (WC_PAGESCROLLERA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS | CS_DBLCLKS | CS_SAVEBITS;
     wndClass.lpfnWndProc   = (WNDPROC)PAGER_WindowProc;
@@ -385,7 +383,6 @@ PAGER_Register (void)
 VOID
 PAGER_Unregister (void)
 {
-    if (GlobalFindAtomA (WC_PAGESCROLLERA))
-	UnregisterClassA (WC_PAGESCROLLERA, (HINSTANCE)NULL);
+    UnregisterClassA (WC_PAGESCROLLERA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/progress.c b/dlls/comctl32/progress.c
index 81e5a88f404..bd22757d7ce 100644
--- a/dlls/comctl32/progress.c
+++ b/dlls/comctl32/progress.c
@@ -361,8 +361,6 @@ PROGRESS_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (PROGRESS_CLASSA)) return;
-
     ZeroMemory (&wndClass, sizeof( WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS | CS_VREDRAW | CS_HREDRAW;
     wndClass.lpfnWndProc   = (WNDPROC)ProgressWindowProc;
@@ -384,7 +382,6 @@ PROGRESS_Register (void)
 VOID
 PROGRESS_Unregister (void)
 {
-    if (GlobalFindAtomA (PROGRESS_CLASSA))
-	UnregisterClassA (PROGRESS_CLASSA, (HINSTANCE)NULL);
+    UnregisterClassA (PROGRESS_CLASSA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/rebar.c b/dlls/comctl32/rebar.c
index 5f3d0fad9b9..289f68fc54b 100644
--- a/dlls/comctl32/rebar.c
+++ b/dlls/comctl32/rebar.c
@@ -2059,8 +2059,6 @@ REBAR_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (REBARCLASSNAMEA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS | CS_DBLCLKS;
     wndClass.lpfnWndProc   = (WNDPROC)REBAR_WindowProc;
@@ -2077,7 +2075,6 @@ REBAR_Register (void)
 VOID
 REBAR_Unregister (void)
 {
-    if (GlobalFindAtomA (REBARCLASSNAMEA))
-	UnregisterClassA (REBARCLASSNAMEA, (HINSTANCE)NULL);
+    UnregisterClassA (REBARCLASSNAMEA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/status.c b/dlls/comctl32/status.c
index 9d550c9a322..0470ac8aba4 100644
--- a/dlls/comctl32/status.c
+++ b/dlls/comctl32/status.c
@@ -1254,8 +1254,6 @@ STATUS_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (STATUSCLASSNAMEA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS | CS_DBLCLKS | CS_VREDRAW;
     wndClass.lpfnWndProc   = (WNDPROC)StatusWindowProc;
@@ -1278,7 +1276,6 @@ STATUS_Register (void)
 VOID
 STATUS_Unregister (void)
 {
-    if (GlobalFindAtomA (STATUSCLASSNAMEA))
-	UnregisterClassA (STATUSCLASSNAMEA, (HINSTANCE)NULL);
+    UnregisterClassA (STATUSCLASSNAMEA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/tab.c b/dlls/comctl32/tab.c
index 09a285d0ec5..236355cce8e 100644
--- a/dlls/comctl32/tab.c
+++ b/dlls/comctl32/tab.c
@@ -1895,10 +1895,8 @@ TAB_Register (void)
 {
   WNDCLASSA wndClass;
 
-  if (GlobalFindAtomA (WC_TABCONTROLA)) return;
-
   ZeroMemory (&wndClass, sizeof(WNDCLASSA));
-  wndClass.style         = CS_GLOBALCLASS | CS_DBLCLKS | CS_SAVEBITS;
+  wndClass.style         = CS_GLOBALCLASS | CS_DBLCLKS | CS_HREDRAW | CS_VREDRAW;
   wndClass.lpfnWndProc   = (WNDPROC)TAB_WindowProc;
   wndClass.cbClsExtra    = 0;
   wndClass.cbWndExtra    = sizeof(TAB_INFO *);
@@ -1913,7 +1911,6 @@ TAB_Register (void)
 VOID
 TAB_Unregister (void)
 {
-  if (GlobalFindAtomA (WC_TABCONTROLA))
     UnregisterClassA (WC_TABCONTROLA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/toolbar.c b/dlls/comctl32/toolbar.c
index c8e5112a191..8f1f894ca52 100644
--- a/dlls/comctl32/toolbar.c
+++ b/dlls/comctl32/toolbar.c
@@ -3759,8 +3759,6 @@ TOOLBAR_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (TOOLBARCLASSNAMEA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS | CS_DBLCLKS;
     wndClass.lpfnWndProc   = (WNDPROC)ToolbarWindowProc;
@@ -3777,7 +3775,6 @@ TOOLBAR_Register (void)
 VOID
 TOOLBAR_Unregister (void)
 {
-    if (GlobalFindAtomA (TOOLBARCLASSNAMEA))
-	UnregisterClassA (TOOLBARCLASSNAMEA, (HINSTANCE)NULL);
+    UnregisterClassA (TOOLBARCLASSNAMEA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/tooltips.c b/dlls/comctl32/tooltips.c
index db3eaee6701..cecf83f5cb3 100644
--- a/dlls/comctl32/tooltips.c
+++ b/dlls/comctl32/tooltips.c
@@ -2393,8 +2393,6 @@ TOOLTIPS_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (TOOLTIPS_CLASSA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS | CS_DBLCLKS | CS_SAVEBITS;
     wndClass.lpfnWndProc   = (WNDPROC)TOOLTIPS_WindowProc;
@@ -2411,7 +2409,6 @@ TOOLTIPS_Register (void)
 VOID
 TOOLTIPS_Unregister (void)
 {
-    if (GlobalFindAtomA (TOOLTIPS_CLASSA))
-	UnregisterClassA (TOOLTIPS_CLASSA, (HINSTANCE)NULL);
+    UnregisterClassA (TOOLTIPS_CLASSA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/trackbar.c b/dlls/comctl32/trackbar.c
index 6a172a34343..6b7cf27205c 100644
--- a/dlls/comctl32/trackbar.c
+++ b/dlls/comctl32/trackbar.c
@@ -1634,8 +1634,6 @@ TRACKBAR_Register (void)
 {
     WNDCLASSA wndClass;
 
-    if (GlobalFindAtomA (TRACKBAR_CLASSA)) return;
-
     ZeroMemory (&wndClass, sizeof(WNDCLASSA));
     wndClass.style         = CS_GLOBALCLASS;
     wndClass.lpfnWndProc   = (WNDPROC)TRACKBAR_WindowProc;
@@ -1652,7 +1650,6 @@ TRACKBAR_Register (void)
 VOID
 TRACKBAR_Unregister (void)
 {
-    if (GlobalFindAtomA (TRACKBAR_CLASSA))
-	UnregisterClassA (TRACKBAR_CLASSA, (HINSTANCE)NULL);
+    UnregisterClassA (TRACKBAR_CLASSA, (HINSTANCE)NULL);
 }
 
diff --git a/dlls/comctl32/updown.c b/dlls/comctl32/updown.c
index 112df8398ef..20ef0e1f562 100644
--- a/dlls/comctl32/updown.c
+++ b/dlls/comctl32/updown.c
@@ -1010,8 +1010,6 @@ UPDOWN_Register(void)
 {
     WNDCLASSA wndClass;
 
-    if( GlobalFindAtomA( UPDOWN_CLASSA ) ) return;
-
     ZeroMemory( &wndClass, sizeof( WNDCLASSA ) );
     wndClass.style         = CS_GLOBALCLASS | CS_VREDRAW;
     wndClass.lpfnWndProc   = (WNDPROC)UpDownWindowProc;
@@ -1034,7 +1032,6 @@ UPDOWN_Register(void)
 VOID
 UPDOWN_Unregister (void)
 {
-    if (GlobalFindAtomA (UPDOWN_CLASSA))
-	UnregisterClassA (UPDOWN_CLASSA, (HINSTANCE)NULL);
+    UnregisterClassA (UPDOWN_CLASSA, (HINSTANCE)NULL);
 }