Microsoft Windows 3.0 Pre-Release 0.1
Released in 1989 by Microsoft
For DOS

This is a very early and stripped down pre-release of Microsoft
Windows 3.0 that was sent to hardware vendors strictly for the
purpose of hardware compatibility testing. As such, it does not
include any applications other than the MS-DOS Executive.

It will only run a small handful of Windows 2.x or 1.x applications,
but you may notice that you can run more of them at once than on
Windows 2.

This software is very, very, very picky about the environment needed 
to run it properly. It requires a 386 or 486 CPU, and DOS 3.31 or 
4.0x. You must add the line FILES=40 (or more) to your config.sys.