So you're telling me an OS with 1.2+ billion users has bugs? I'm shocked! :)

On a more serious note, Microsoft is (was?) famous for its QA processes. They have (had?) huge computer farms, tens of thousands of machine to be able to QA with every strange configuration out there. Windows, despite the hate it gets, is one of the most QAd pieces of software out there.

And considering the shoddy architecture it has to support for backwards compatibility (CP/M, MS-DOS, Win32), it works amazingly well.

My impression was that they have changed the way potential releases are tested internally https://www.theregister.co.uk/2018/10/23/microsoft_windows_1... The last update was blocked since files were being deleted in users' Document directories and now this external drive issue. Both cases involve some fairly common configurations.

Yea, I always wondered about the (frankly amazing) backwards compatibility. Windows could probably be a much better system if they just get rid of support for these old systems. Same for these super old MS-Word formats. Doesn't need to be as drastic as Apple does it, though.

The super old MS Word formats are just a memory dump of internal data structures. The Modern DOCX just converts XML into that same representation along with whatever new features have been added. There is little reason to remove the old format when it is still very much an integral part of Word internals.