Introduction
If you want your application have just only instance is run in the same time, you only download and use it.
Step 1: Add file "LimitSingleInstance.h" to your project. This file is written by Microsoft. :-)
Step 2: Run UUIDGEN.EXE to get ID. This tool is written by Micorosft :-)
Step 3: Declare a variable
CLimitSingleInstance g_SingleInstanceObj(TEXT("{ID get from UUIDGEN}"));
for ex: CLimitSingleInstance g_SingleInstanceObj(TEXT("{addb6c1d-d98d-40f4-8041-0eb6b8bc884c}"));
Step 4: InitInstance()
Only add this line to check instance and make sure only 1 instance can run.
if (g_SingleInstanceObj.IsAnotherInstanceRunning())
return FALSE;
VERY and VERY SIMPLE.
I get this information and "LimitSingleInstance.h" from KnowledgeBase of Mirosoft site.