How to use step by step
1. Download it from here http://www.rarlab.com/rar/wrar371.exe
2. Double click on the download file to install, takes a few seconds
And that's it installed, so when you download a file from any site.
3. Right click on the file and choose extract to "File Name" file name will be filled in with the name of the file.
That simple, also Winrar handles all the compressed files even Zip Files