But the implication of the above comment was not that the programs would disappear, just the company. (I mean, any online authorizations would die, but I didn't think that was part of daily routines, just installations. Though I really know nothing of MS business-type servers (SQLServer etc))

...and I'm desperately trying to hold in comments about the small difference in performance between 1980s and MS software - I honestly blame Outlook for how the world killed email as an effective medium.

Though I do count myself lucky to have my current job. I've worked public sector in the past, and recently started up a 2nd (part time) job at a university that involves using Outlook. It is quite painful.

count yourself lucky, you could be using lotus notes

Highly prevalent != irreplaceable (though it might be a prerequisite). The fact that so many businesses/sectors use MS technology is what makes them one of the "Big 4." However, there is nothing irreplaceable about those technologies. Another vendor/technology could replace them if those businesses were forced to change due to MS disappearing.