Surely you can override this warning with most AV products?
I would have thought you can obtain an MD5 checksum of a known good copy of the installer, check your download against it, and if all is well, just direct your AV to quit squawking about it.
Or am I missing something here? And how would a W10 upgrade help anyway?
I've seen plenty of cases where AV gets it wrong, and most of them let you do something about it.
Also, have we ruled out a real problem with the installer e.g. perhaps a mirror has been compromised? Also not impossible.
Charles Meo