diff --git a/mercurial/cmdutil.py b/mercurial/cmdutil.py
--- a/mercurial/cmdutil.py
+++ b/mercurial/cmdutil.py
@@ -613,6 +613,7 @@ def service(opts, parentfn=None, initfn=
         except AttributeError:
             pass
         os.unlink(lockpath)
+        util.hidewindow()
         sys.stdout.flush()
         sys.stderr.flush()
 
diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -529,6 +529,14 @@ else:
 def lookup_reg(key, name=None, scope=None):
     return None
 
+def hidewindow():
+    """Hide current shell window.
+
+    Used to hide the window opened when starting asynchronous
+    child process under Windows, unneeded on other systems.
+    """
+    pass
+
 if os.name == 'nt':
     from windows import *
 else:
diff --git a/mercurial/win32.py b/mercurial/win32.py
--- a/mercurial/win32.py
+++ b/mercurial/win32.py
@@ -16,7 +16,7 @@ used.
 import win32api
 
 import errno, os, sys, pywintypes, win32con, win32file, win32process
-import winerror
+import winerror, win32gui
 import osutil, encoding
 from win32com.shell import shell, shellcon
 
@@ -172,3 +172,12 @@ def set_signal_handler_win32():
         win32process.ExitProcess(1)
     win32api.SetConsoleCtrlHandler(handler)
 
+def hidewindow():
+    def callback(*args, **kwargs):
+        hwnd, pid = args
+        wpid = win32process.GetWindowThreadProcessId(hwnd)[1]
+        if pid == wpid:
+            win32gui.ShowWindow(hwnd, win32con.SW_HIDE)
+
+    pid =  win32process.GetCurrentProcessId()
+    win32gui.EnumWindows(callback, pid)