Windows 3.15

This version is a fake. This version integrates the taskbar of Chicago. As noticed at https://www.betaarchive.com/forum/viewtopic.php?f=16&t=502, where it was claimed to be an 'update of 3.1 to test taskbar functionality' - it is certainly a fake; however, Microsoft did make a shell test for Windows 3.5x, called the NewShell.