Is it possible to elevate privileges in "Command Prompt" without having to open new "Administrator: Command Prompt" ?

What are you trying to do? Depending on if you are logged in as admin and what level you have UAC set at it can vary: Win Key Cmd Cntrl+Shift+Enter Otherwise if you are already working in an open command prompt or are running a batch file, I think you have to use the runas syntax, but you'll have to experiment with how UAC behaves when you do that.