.rar files are not video files. They are a compression file which can be filled with any kind of data. Videos, pictures, text docs etc etc. To extract the files within the .rar you'll need winrar.
http://www.rarlab.com/download.htm . Select the 'English (32 bit) link on that page and install the file it downloads. Then you should be able to right click the rar files you have downloaded and select 'extract to'. I hope this helps