diff --git a/reactos/ntoskrnl/ke/clock.c b/reactos/ntoskrnl/ke/clock.c
index 401fc6b0b12..f2eb528a618 100644
--- a/reactos/ntoskrnl/ke/clock.c
+++ b/reactos/ntoskrnl/ke/clock.c
@@ -247,18 +247,15 @@ KeUpdateRunTime(IN PKTRAP_FRAME  TrapFrame,
                 IN KIRQL  Irql)
 {
     PKPRCB Prcb = KeGetCurrentPrcb();
-    PKTHREAD CurrentThread;
-    PKPROCESS CurrentProcess;
+    PKTHREAD CurrentThread = Prcb->CurrentThread;
+    PKPROCESS CurrentProcess = CurrentThread->ApcState.Process;
 
-    /* Make sure we don't go further if we're in early boot phase. */
-    if (!(Prcb) || !(Prcb->CurrentThread)) return;
-
-    /* Get the current thread and process */
-    CurrentThread = Prcb->CurrentThread;
-    CurrentProcess = CurrentThread->ApcState.Process;
+    /* Increase interrupt count */
+    Prcb->InterruptCount++;
 
     /* Check if we came from user mode */
-    if (TrapFrame->PreviousPreviousMode != KernelMode)
+    if ((TrapFrame->EFlags & EFLAGS_V86_MASK) ||
+        (TrapFrame->SegCs & MODE_MASK))
     {
         /* Update user times */
         CurrentThread->UserTime++;
@@ -267,6 +264,9 @@ KeUpdateRunTime(IN PKTRAP_FRAME  TrapFrame,
     }
     else
     {
+        /* Update CPU kernel time in all cases */
+        Prcb->KernelTime++;
+
         /* Check IRQ */
         if (Irql > DISPATCH_LEVEL)
         {
@@ -284,9 +284,6 @@ KeUpdateRunTime(IN PKTRAP_FRAME  TrapFrame,
             /* This was DPC time */
             Prcb->DpcTime++;
         }
-
-        /* Update CPU kernel time in all cases */
-        Prcb->KernelTime++;
    }
 
     /* Set the last DPC Count and request rate */
@@ -295,7 +292,9 @@ KeUpdateRunTime(IN PKTRAP_FRAME  TrapFrame,
                              Prcb->DpcRequestRate) / 2;
 
     /* Check if we should request a DPC */
-    if ((Prcb->DpcData[0].DpcQueueDepth) && !(Prcb->DpcRoutineActive))
+    if ((Prcb->DpcData[0].DpcQueueDepth) &&
+        !(Prcb->DpcRoutineActive) &&
+        !(Prcb->DpcInterruptRequested))
     {
         /* Request one */
         HalRequestSoftwareInterrupt(DISPATCH_LEVEL);
@@ -335,7 +334,8 @@ KeUpdateRunTime(IN PKTRAP_FRAME  TrapFrame,
     * we don't care about the quantum value anymore after the QuantumEnd
     * flag is set.
     */
-    if ((CurrentThread->Quantum -= 3) <= 0)
+    if (((CurrentThread->Quantum -= 3) <= 0) &&
+        (Prcb->IdleThread != CurrentThread))
     {
         Prcb->QuantumEnd = TRUE;
         HalRequestSoftwareInterrupt(DISPATCH_LEVEL);
@@ -414,6 +414,10 @@ KeUpdateSystemTime(IN PKTRAP_FRAME TrapFrame,
         KiTickOffset += KeMaximumIncrement;
         KeUpdateRunTime(TrapFrame, Irql);
     }
+
+    /* Return from the interrupt */
+    Ke386DisableInterrupts();
+    HalEndSystemInterrupt(Irql, 0);
 }
 
 /*
diff --git a/reactos/ntoskrnl/ke/i386/clock.S b/reactos/ntoskrnl/ke/i386/clock.S
new file mode 100644
index 00000000000..ee90fd31408
--- /dev/null
+++ b/reactos/ntoskrnl/ke/i386/clock.S
@@ -0,0 +1,113 @@
+/*
+ * FILE:            ntoskrnl/ke/i386/clock.S
+ * COPYRIGHT:       See COPYING in the top level directory
+ * PURPOSE:         System Clock Management
+ * PROGRAMMER:      Alex Ionescu (alex@relsoft.net)
+ */
+
+/* INCLUDES ******************************************************************/
+
+#include <asm.h>
+#include <internal/i386/asmmacro.S>
+.intel_syntax noprefix
+
+/* GLOBALS *******************************************************************/
+
+.extern _KeTimeAdjustment
+.extern _KiTickOffset
+.extern _KeTickCount
+.extern _KeMaximumIncrement
+
+/* FUNCTIONS ******************************************************************/
+
+.globl _KeUpdateSystemTime2@0
+.func KeUpdateSystemTime2@0
+_KeUpdateSystemTime2@0:
+
+    /* Get shared data in ECX */
+    mov ecx, USER_SHARED_DATA
+
+    /* Get interrupt time */
+    mov edi, [ecx+USER_SHARED_DATA_INTERRUPT_TIME]
+    mov esi, [ecx+USER_SHARED_DATA_INTERRUPT_TIME+4]
+
+    /* Add the increment and get the carry */
+    add edi, eax
+    adc esi, 0
+
+    /* Now store the updated times */
+    mov [ecx+USER_SHARED_DATA_INTERRUPT_TIME+8], esi
+    mov [ecx+USER_SHARED_DATA_INTERRUPT_TIME], edi
+    mov [ecx+USER_SHARED_DATA_INTERRUPT_TIME+4], esi
+
+    /* Substract tick count and get the low count */
+    LOCK sub _KiTickOffset, eax
+    mov eax, _KeTickCount
+    mov ebx, eax
+    jg IncompleteTick
+
+    /* Get shared data in ECX */
+    mov ebx, USER_SHARED_DATA
+
+    /* Get system time */
+    mov edi, [ebx+USER_SHARED_DATA_SYSTEM_TIME]
+    mov esi, [ebx+USER_SHARED_DATA_SYSTEM_TIME+4]
+
+    /* Add the increment and get the carry */
+    add ecx, _KeTimeAdjustment
+    adc edx, 0
+
+    /* Now store the updated times */
+    mov [ebx+USER_SHARED_DATA_SYSTEM_TIME+8], edx
+    mov [ebx+USER_SHARED_DATA_SYSTEM_TIME], ecx
+    mov [ebx+USER_SHARED_DATA_SYSTEM_TIME+4], edx
+
+    /* Put tick count back in EBX */
+    mov ebx, eax
+
+    /* Copyit in ECX and get hich count */
+    mov ecx, eax
+    mov edx, _KeTickCount + 4
+
+    /* Add the increment and get the carry */
+    add ecx, 1
+    adc edx, 0
+
+    /* Now store the updated tick */
+    mov [_KeTickCount+8], edx
+    mov [_KeTickCount], ecx
+    mov [_KeTickCount+4], edx
+
+    /* Store in in shared data too */
+    mov [USER_SHARED_DATA+USER_SHARED_DATA_TICK_COUNT+8], edx
+    mov [USER_SHARED_DATA+USER_SHARED_DATA_TICK_COUNT], ecx
+    mov [USER_SHARED_DATA+USER_SHARED_DATA_TICK_COUNT+4], edx
+
+IncompleteTick:
+
+    /* Queue DPC to handle registered timers */
+
+    /* Check if this was a full tick */
+    cmp dword ptr _KiTickOffset, 0
+    jg IncompleteTick2
+
+    /* Increase tick offset */
+    mov eax, _KeMaximumIncrement
+    add _KiTickOffset, eax
+
+    /* Update system run time */
+    push esp
+    call _KeUpdateRunTime@8
+    jmp Done
+
+IncompleteTick2:
+    /* Increase interrupt count */
+    inc dword ptr [fs:KPCR_PRCB_INTERRUPT_COUNT]
+
+Done:
+    /* Exit the interrupt */
+    mov esi, $
+    cli
+    call _HalEndSystemInterrupt@8
+    jmp _Kei386EoiHelper@0
+.endfunc
diff --git a/reactos/ntoskrnl/ke/i386/irq.c b/reactos/ntoskrnl/ke/i386/irq.c
index 58334437dff..158cd165bd8 100644
--- a/reactos/ntoskrnl/ke/i386/irq.c
+++ b/reactos/ntoskrnl/ke/i386/irq.c
@@ -156,7 +156,7 @@ KiInterruptDispatch (ULONG vector, PKIRQ_TRAPFRAME Trapframe)
    if (KiClockSetupComplete)
    {
       KeIRQTrapFrameToTrapFrame(Trapframe, &KernelTrapFrame);
-      KeUpdateSystemTime(&KernelTrapFrame, old_level, 100000);
+      return KeUpdateSystemTime(&KernelTrapFrame, old_level, 100000);
    }
 
    /*
diff --git a/reactos/ntoskrnl/ntoskrnl.rbuild b/reactos/ntoskrnl/ntoskrnl.rbuild
index 54aa934f475..784f7d02183 100644
--- a/reactos/ntoskrnl/ntoskrnl.rbuild
+++ b/reactos/ntoskrnl/ntoskrnl.rbuild
@@ -29,6 +29,7 @@
 				<file first="true">main_asm.S</file>
 				<file>cpu.S</file>
 				<file>ctxswitch.S</file>
+                <file>clock.S</file>
 				<file>exp.c</file>
 				<file>fpu.c</file>
 				<file>gdt.c</file>