- When Microsoft and IBM had their divorce, Microsoft left OS/2 in the rear view mirror and began driving toward NT. This marked the third operating system that Microsoft had fully intended to replace MS-DOS and Windows on the IBM PC and compatibles. The first such system was Xenix, the second was OS/2, and finally NT. The question that remained for Microsoft was which version of NT will accomplish this goal? Version 3.1, the first NT version, was successful for Microsoft internally, and NT 4 was a commercial success. This commercial success made certain that Microsoft would create NT 5, which began its planning phase in the summer of 1996 after the launch of NT 4 with the planned timing for release being in late 1997. This had been revised by the Windows Hardware Engineering Conference in May of 1997 to a ship date sometime in 1998. At this point, there was an intent to have a version for Intel’s Merced, for both 32 bit and 64 bit Alpha, for x86 workstations, and for consumer PCs. Here we see that Microsoft had pivoted from making a pure successor to NT 4, to having NT 5 be the version that unified the consumer and professional operating system lines, and the company had roughly forty two hundred people working on it…