diff --git a/reactos/include/ntos/ntdef.h b/reactos/include/ntos/ntdef.h
index e9a6b6aa341..4b3eb851277 100644
--- a/reactos/include/ntos/ntdef.h
+++ b/reactos/include/ntos/ntdef.h
@@ -32,18 +32,45 @@
 # define PROBE_ALIGNMENT(_s) TYPE_ALIGNMENT(DWORD)
 #endif
 
+
+#if defined(_MSC_VER)
+   #define Const64(a) (a##i64)
+   static __inline LARGE_INTEGER MK_LARGE_INTEGER(__int64 i)
+   {
+      LARGE_INTEGER li;
+      li.QuadPart = i;
+      return li;
+   }
+   #define INIT_LARGE_INTEGER(a) {{(ULONG)a, (LONG)(a>>32)}}   
+#elif defined (__GNUC__)
+   #define Const64(a) (a##LL)
+   #define MK_LARGE_INTEGER(a) ((LARGE_INTEGER)(LONGLONG)(a))
+   #define INIT_LARGE_INTEGER(a) MK_LARGE_INTEGER(Const64(a))    
+#endif
+
+#define LargeInteger0 MK_LARGE_INTEGER(0)
+
+
+/* Compile time asserts */
+#define C_ASSERT(e) do{extern char __C_ASSERT__[(e)?1:-1]; (void)__C_ASSERT__;}while(0)
+
+
 /* Helpers for easy conversion to system time units (100ns) */
 #define ABSOLUTE_TIME(wait) (wait)
 #define RELATIVE_TIME(wait) (-(wait))
-#define NANOS_TO_100NS(nanos) (((LONGLONG)(nanos)) / 100L)
-#define MICROS_TO_100NS(micros) (((LONGLONG)(micros)) * NANOS_TO_100NS(1000L))
-#define MILLIS_TO_100NS(milli) (((LONGLONG)(milli)) * MICROS_TO_100NS(1000L))
-#define SECONDS_TO_100NS(seconds) (((LONGLONG)(seconds)) * MILLIS_TO_100NS(1000L))
+#define NANOS_TO_100NS(nanos) (((LONGLONG)(nanos)) / 100)
+#define MICROS_TO_100NS(micros) (((LONGLONG)(micros)) * NANOS_TO_100NS(1000))
+#define MILLIS_TO_100NS(milli) (((LONGLONG)(milli)) * MICROS_TO_100NS(1000))
+#define SECONDS_TO_100NS(seconds) (((LONGLONG)(seconds)) * MILLIS_TO_100NS(1000))
+#define MINUTES_TO_100NS(minutes) (((LONGLONG)(minutes)) * SECONDS_TO_100NS(60))
+#define HOURS_TO_100NS(hours) (((LONGLONG)(hours)) * MINUTES_TO_100NS(60))
+
+
 
 
 /* Helpers for enumarating lists */
 #define LIST_FOR_EACH(entry, head) \
-   for(entry = (head)->Flink; entry != (head); entry = entry->Flink)
+   for((entry) = (head)->Flink; (entry) != (head); (entry) = (entry)->Flink)
 
 /* 
 Safe version which saves pointer to the next entry so the current ptr->field entry