Index: base/applications/regedit/framewnd.c
===================================================================
--- base/applications/regedit/framewnd.c	(revision 72521)
+++ base/applications/regedit/framewnd.c	(working copy)
@@ -1316,7 +1316,7 @@
             return DefWindowProcW(hWnd, message, wParam, lParam);
         break;
     case WM_ACTIVATE:
-        if (LOWORD(hWnd))
+        if (LOWORD(hWnd) && g_pChildWnd)
             SetFocus(g_pChildWnd->hWnd);
         break;
     case WM_SIZE: