It supports upgrades by installing right over an existing copy, preserving all settings. PeaZip Portable is packaged in a Installer so it will automatically detect an existing installation when your drive is plugged in.

This software is released under Open Source LGPLv3 license, free for any use (private and professional). Cross-platform, full-featured but user-friendly alternative to WinRar, WinZip and similar general purpose archive manager applications, open and extract 180+ archive formats: 001, 7Z, ACE(*), ARC, ARJ, BZ2, CAB, DMG, GZ, ISO, LHA, PAQ, PEA, RAR, TAR, UDF, WIM, XZ, ZIP ZIPX - view full list of supported archive file formats for archiving and for extraction. PeaZip is free file archiver utility, based on Open Source technologies of 7-Zip, p7zip, FreeArc, PAQ, and PEA projects. Update automatically or install from the portable app store in the Platform. And it's open source and completely free. It's packaged in Format so it can easily integrate with the Platform. PeaZip Portable is an easy to use PeaZip file archiver with support for 7z, ZIP, GZIP, BZIP2, TAR, RAR files and more packaged as a portable app. A new version of PeaZip Portable has been released.