7-zip
works in win 98/me/nt/2000/xp. free software. distributed under the gnu lesser general public license (lgpl). go grab it. very useful.
- packing & unpacking: 7z, ZIP, GZIP, BZIP2 and TAR
- unpacking only: RAR, CAB, ARJ, LZH, CHM, Z, CPIO, RPM and DEB
