Microsoft Windows 3.0a
Released 10/31/1990 by Microsoft
For DOS

Image quality: Used

Windows 3.x was the first to gain significant development and 
commercial traction. It combined the 8086, 286, and 386 modes of 
Windows 2 in to one package. It replaced the MSDOS Executive with a 
Program Manager and File Manager similar to those in OS/2 1.x. Much 
of its success was spurred by the availability and success of 
Microsoft Office.