It is true that Explorer has been replaced with Edge, but Windows internals have anticipated for that.
What is your exact version (home, pro, etc) and build? You can use 'winver' to find out: press win-r, enter "winver" without quotes and it will mention the version, build and type. Also: from where did you get the installer? Did you use somerhing you kept around or did you download a new copy from the Adobe website?
I'm convinced that part of your problem could be update related. See, the current Windows version is 2004, this has been available for several months already (we're even close to the next update) so you're not on the latest version. So if the installer complains about updates then this might be related.
Though it does seem strange of course because from a technical perspective there isn't that much difference.