Really? I thought it was because they don't plan to release another major version of windows, and wanted the number to have a nice solid "10", rather than a "9"
Idiots wrote code that says if osversion.startsWith('Windows 9') this is some crufty old Win9x system.
To revert to the actual topic, to defend against this type of thing the QUIC binding for HTTP assigns an arbitrary non-contiguous group of identifiers as reserved to be ignored in various places, with the intent that some real systems will prod these once in a while, to discourage idiots hard-coding checks that will become obsolete.
As far as I've seen, there was never any proof that Microsoft chose the Windows 10 name for that reason. I find it especially unlikely considering Vista broke even more recent compatibility.
My recollection is that MS did confirm that Windows 10 was chosen for some vague mention of technical reasons, which most people latched on to as being explained by the "Windows 9" check.
I have seen code in the 2010s that did explicitly check for "Windows 9" as a means to check if it was running on Windows 95 or 98. That doesn't mean that the code would actually work on those systems (it could well be a prelude to saying "your system is too ancient, we don't support you"). But such kind of cruft tends to last a very, very long time without active maintenance.
Really? I thought it was because they don't plan to release another major version of windows, and wanted the number to have a nice solid "10", rather than a "9"