You can Unrar files using a portable app called Rarzilla. It allows you to unzip, unrar, untar and ungz any file by simply dragging that compressed file over the main picture in the Rarzilla app.
Optimized RarZilla-Version for mobile purposes: “RarZilla Free Unrar Portable” is smaller, optimized for mobile use – e.g. on an USB-Stick – and comes without setup routine.
Just extract all files and “RarZilla Free Unrar Portable” is ready to be used. You can place it on your USB flash drive, iPod, portable hard drive or a CD and use it on any computer, without leaving any personal information behind.