WinRAR versions before 5.0 do not support RAR5 archives only older versions of WinRAR run on Windows versions prior to XP, and cannot open RAR5 archives. Support for the archive format RAR5, using the same RAR file extension as earlier versions, was added in version 5.0 the older RAR file format has since been referred to as RAR4. WinRAR and the RAR file format have evolved over time.