Hallo Sergey
I doing this in may main Apps

declare Integer CreateMutex in win32api integer, integer, string
declare Integer GetLastError in win32api
CreateMutex(0, 0, "MutexTest")
if GetLastError()=183
if messagebox("Programm still running on this maschine,";
+chr(13)+chr(10);
+"do you want to restart ?",276 ")=6 && Yes
else
return
endif
endif

Regards from Germany
Winfried