i am using this function from my web application to call exe file . when it calls .exe file every thing happens accurately, i can see it as running process in task manager proce
IIS and its child processes are running in different (and windowless) session. So you can't see if window is open. Also some processes may behave strangly due this (you probably did not hit such issues, and unlikly to have problems with console apps).
You can see it by turning on "Session ID" column in task manager: View -> Select columns-> Session ID (on processes tab).