Thank you for your efforts...
Single Instance help me not to open calculator more then once. This is wonderful. But, suppose I am running a software, opened calculator once made a calculation and turned back to software, say MS Word. Now the software is running in front and calculator cannot be seen. When I need the calculator again, I pushed the calculator button on the keyboard! Now Single Instance closes the second calculator (which is in front), but I obviously need calculator in front??? Is it possible to bring the only instance in front on the desktop (if it is not a big deal)??