While MS-DOS 3.3 was released in 1987, there was not (in reality) much improvement over DOS 3.2, so many of us didn't bother to upgrade if we didn't see the "new" features useful. The only real improvement (to many) was not until Win 6.0, which I did have (I just can't remember if it was purchased outright, or inherited) in the original 3.5" disk format; I later updated that to Win 6, then Win 6.22. I ran DOS 6.22 (with supplemental additions) with Win 3.1/WfWG 3.11 until Win 95 came out (as an upgrade.) That eventually became Win 98. The K6-2/450 processor and the motherboard's maximum of only 768 kB of memory made it unthinkable to upgrade to XP.