If you use Windows 圆4, it is strongly recommended to install 64 bit WinRAR version. Since version 3.90 is also a WinRAR version for Windows 圆4 is available.
WinRARs main features are very strong general and multimedia compression, solid compression, archive protection from damage, processing of ZIP and other non-RAR archives, scanning archives for viruses, programmable self-extracting archives(SFX), NTFS and Unicode support, strong AES encryption, support of multivolume archives, command line and graphical interface, drag-and-drop facility, wizard interface, theme support, folder tree panel, password manager and multithread support. WinRAR is a 32-bit/64-bit Windows version of RAR Archiver, the powerful archiver and archive manager.