my command prompt is disappearing ...it does not stay for a single moment..it disappears while it is opened..
How are you opening it? If you're typing a command into the Run box, the form will only flash up for half a second. You only need to type cmd into the Run box (Windows key and R) and the form will pop up and remain up. As a shortcut, and only if you know the command you want, type, for example, cmd /k ipconfig /all into the run box then the entire command is recognised.