Sometimes it so happens that while executing the program for the result the o/p is continuous or gets stuck in the DOS shell.

my Question: Is there any command to quit this shell and return to the main program or C shell directly.

Are you actually talking about DOS Shell and C Shell or just the Windows command prompt / MS DOS?

I don't know about the former two, but in the latter two try Ctrl-C.

'm taking abt C shell and DOS Shell, when we execute/run a program it goes to the DOS shell right....sometimes due to some error like improper loop endings the programs o/p becomes continous.....in tat case i forcibly exit the program.... i want to know if there's any shortcut to exit the DOS shell and returnin to C without exiting..... Hope u got me...??

It sounds like you are using MS Visceral C++?
And when you run a program from there it starts a msdos console for your program to run and normally when it ends the console disapears but when you have and error that creates endless loop you're stuck?

What, is it running full screen? ...and you can't click on the X box in the top right corner?
If you hit ctrl-alt-delete keys simultaneously the task manger will come up and you can select the process (it will have your program name) and then "select end process".

There is probably a way to change the way that console opens by default.
It might be as simple as changing the console preferences for the Start>Accessories>MSDOS console starter icon.
Just right click on it and I think you can select properties or something like that.