i am using windows xp professional but my command prompt was not working if we click the run comand and press the cmd then it was not working if we enter d: it was opening the d drive and enter notepad the notepad also open but the command prompt was not opening
point at the window where you want a command prompt. left click once. Now you should see the command prompt flashing.
If this does not work, let the forum know, we can help you with a system restore. The system restore can set the system back to a time before the problem started.