Open rar file You are here: > Open rar file A RAR file is an archive created by WinRAR application. The RAR file is a data container which holds one or multiple files and folders. RAR file uses its proprietary compression algorithm to compress data in it. When compressing large file sets, the RAR file can be split into multiple parts. It can also be encrypted with a password to protect important files. To open RAR file, please follow the steps, • Run PowerISO. • Click the 'Open' button on toolbar or choose 'File > Open' menu.