Either you are compiling the source as a C program instead of C++ or... well, actually that's it. If the compiler is set up correctly, it should know where it's own standard includes are. Try replacing #include <iostream> with #include <stdio.h>, if that works you are using the wrong compiler.
There's no such file. You've made a spelling mistake. Perhaps you made similar spelling mistake on iostream.
turbo c++ compiler using a dosbox0.74 in windows7 64 bit.
I see. Which version of Turbo C++ is it? If you have to run it under DOS, I'm guessing pretty old. Maybe you've got such an old version that it just isn't compliant to the standard. Get yourself something more recent.
It's stdio.h, NOT studio.h - i made the same mistake when I started. if it runs in dosbox, it might not be standard conform, in that case you'd have to include iostream.h instead of iostream. If that's the case though, I'd recommend you to not use it, unless it's enforced by your professor or something.
you need to add <cstdlib> for that system command to work on any other compiler. be careful when posting code from microsoft compilers they allow you to use functions from various header files without them actually being included.