7-Zip

Full history/changelog

9.32 alpha, released on 2013-12-01, raised the required Windows version to Windows 2000, dropping support for Win9x. The last alpha release before that is 9.30 alpha, released on 2012-10-26. The last stable release before that is 9.20, released on 2010-11-18.

This seems to be the only time that the required Windows version is raised; 26.00, latest as of writing this, still supports Windows 2000.

retro7zip is a port of newer 7-Zip CLI to DOS and Win32c (i.e. 32-bit Win95 application). The GUI applications, 7zFM and 7zG, aren't included in the port. VOGONS thread

WinRAR

According to Win3x.org and Wikipedia:

Windows
version
WinRAR
version
Source
NT 3.12.00
NT 3.52.01
3.1, NT 3.512.06
953.80
98, Me, NT 4.03.9320110127
20004.1120140801
XP6.0220260420
Vista, and all 32-bit7.0120260420

Changelog prior to Version 2.70 was on ftp://rarsoft.ti.sk/pub/rar/WhatsNew.txt, and all FTP links were unarchived by Wayback Machine.

The dropping of Win95 support wasn't mentioned in the changelog.