Your favorite, UPGRADED!
7-Zip Portable is a great way to take your file compression and extraction tools with you wherever you go. This handy app lets you work with a wide variety of archive formats like ZIP, RAR, 7z, and many more, all without needing to install anything on the computer you're using. Just put it on a USB drive, and you're ready to compress files to save space, extract downloaded archives, or encrypt sensitive data on any Windows computer.
(note: this version has no installer)