From 58f165a05217e8712d19e2197e24eeaebda693e7 Mon Sep 17 00:00:00 2001
From: Johannes Anderwald <johannes.anderwald@reactos.org>
Date: Thu, 6 Sep 2007 19:45:26 +0000
Subject: [PATCH] - there can be only one instance of the device manager

svn path=/trunk/; revision=28905
---
 .../base/applications/mscutils/devmgmt/devmgmt.c  | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/reactos/base/applications/mscutils/devmgmt/devmgmt.c b/reactos/base/applications/mscutils/devmgmt/devmgmt.c
index e1b6e7ff959..96424dcaafd 100644
--- a/reactos/base/applications/mscutils/devmgmt/devmgmt.c
+++ b/reactos/base/applications/mscutils/devmgmt/devmgmt.c
@@ -11,6 +11,7 @@
 
 HINSTANCE hInstance;
 HANDLE ProcessHeap;
+HANDLE hMutex;
 
 int WINAPI
 _tWinMain(HINSTANCE hThisInstance,
@@ -24,6 +25,18 @@ _tWinMain(HINSTANCE hThisInstance,
     int Ret = 1;
     INITCOMMONCONTROLSEX icex;
 
+    hMutex = CreateMutex(NULL, TRUE, _T("devmgmt_mutex"));
+    if (hMutex == NULL || GetLastError() == ERROR_ALREADY_EXISTS)
+    {
+        if (hMutex)
+        {
+            CloseHandle(hMutex);
+        }
+        return 0;
+    }
+
+
+
     hInstance = hThisInstance;
     ProcessHeap = GetProcessHeap();
 
@@ -59,7 +72,7 @@ _tWinMain(HINSTANCE hThisInstance,
     }
 
     LocalFree((HLOCAL)lpAppName);
-
+    CloseHandle(hMutex);
     return Ret;
 }