Expanded source code

Hello.
This is Anuj Gupta, an MCA student from India.
I want to know how can i see the expanded source code after the preprocessor action.
I have read in a book that this can be done by using the "cpp" command in DOS shell, but it did't work out whenver I tried it.
Please, whosoever can help me, kindly reply with a prompt answer.
Take care.

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