This won't be compatible with Windows applications.
On 3-Feb-09, at 5:25 PM, cfinck(a)svn.reactos.org wrote:
  Author: cfinck
 Date: Tue Feb  3 16:25:39 2009
 New Revision: 39353
 URL: 
http://svn.reactos.org/svn/reactos?rev=39353&view=rev
 Log:
 Gabriel Ilardi (gabrielilardi(a)hotmail.it)
 - Allow only one instance of Task-Manager to be run at the same time
 See issue #3976 for more details.
 Modified:
    trunk/reactos/base/applications/taskmgr/taskmgr.c
 Modified: trunk/reactos/base/applications/taskmgr/taskmgr.c
 URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/base/applications/taskmgr/…
 =
 =
 =
 =
 =
 =
 =
 =
 ======================================================================
 --- trunk/reactos/base/applications/taskmgr/taskmgr.c [iso-8859-1]
 (original)
 +++ trunk/reactos/base/applications/taskmgr/taskmgr.c [iso-8859-1]
 Tue Feb  3 16:25:39 2009
 @@ -51,6 +51,12 @@
     HANDLE hProcess;
     HANDLE hToken;
     TOKEN_PRIVILEGES tkp;
 +    HANDLE hMutex;
 +
 +    /* check wether we're already running or not */
 +    hMutex = CreateMutexW(NULL, TRUE, L"taskmgrros");
 +    if ((!hMutex) || (GetLastError() == ERROR_ALREADY_EXISTS))
 +        return 1;
     /* Initialize global variables */
     hInst = hInstance;
 
Best regards,
Alex Ionescu