Was he though? This is someone speaking from the outside, with fuzzy memories of release dates, but I'm pretty sure Windows (excepting NT) didn't have preemptive multitasking until 2000, and I think OS/2 was out before NT. I still have fond memories from the late 90's of a friend who adminned Windows and had a CD for when someone would set the password on the screensaver on the Windows boxes: the CD had an autorun that would pluck the password out of the registry and put it in the clipboard so you could paste it into the password box (no memory protection). That and the memory shotgunner: a program that would write random data to random memory addresses. No Windows machine would stay up for more than about 5 minutes running that, while Linux would kill the program and merrily continue on its way. Or the packet of doom to lock up Windows remotely.
Win95 had preemptive multitasking. Win 3.1 had cooperative multitasking. The "multiuser" aspect of Win95 wasn't secure at all, it was more for letting multiple users have separated settings (e.g., browser bookmarks). However, even that often failed because software would assume a single user and store all the settings in a common location. Since there was no real security in FAT32 filesystems that was pretty easy to do.
I may be splitting hairs at this point, but I think we're both partly right; according to Wikipedia (https://en.wikipedia.org/wiki/Preemption_%28computing%29), Windows 95, 98 and ME had preemptive multitasking for 32 bit programs, but not 16 bit (which would have been the majority at the time of release of Win95). My confusion may come from remembering running multiple DOS and Windows programs at the same time in OS/2 with nary a hiccup and being able to tweak settings (such as RAM allotments).
