Now this is where you will need command prompt portable. Make sure that this is a clean installation, and not one that you have messed around with already. Navigate to %yourdrive%\PortableApps\CommandPromptPortable, and copy all the files in there and go back one level and create a new folder called Run Rar (or whatever you want) and paste those files in that folder. Then in the same folder, navigate to the Settings folder and edit the commandprompt.bat