I am aware that many versions of Windows do not have built-in explorer support for zip files (PKZip format) that use AES-256 encryption as opposed to the broken zip crypto. In particular I have tried it on Windows 7 and Server 2012 and it doesn't work on either.
I don't have access to test newer Windows versions. Can users of Windows 8.1 and/or Windows 10 extract AES-256 encrypted files in zip archives using Windows Explorer or anything that comes with the OS? (I know they can do so by installing freely available programs, but don't want to require them to do so if it's not necessary.)
Best Answer
I tried this right now. I used 7-Zip to create an AES-256 encrypted *.zip (PKZip) file and then open it in Windows 10 File Explorer.
I'm using Windows 10 1709 (OS build 16299.125) aka "Fall Creator's Update".
File Explorer listed the files in the zip file correctly (this is expected as zip files do not encrypt filenames), but gave me an error when attempting to extract a file:
So, no, Windows 10 (and presumably Windows 8.1, 8.0, 7, etc) does not support AES-256 encryption in zip files - however the "ZipCrypto" mode in 7-Zip does seem to be supported.