Cairo wrote:
From /. (of course!)

This reminds me of when Windows 3.0 checked specifically for whether the underlying DOS was MS-DOS, and threw an error if it wasn't.



For starters this is nothing like that.  Also, Larry Osterman has an interesting explanation about that MSDOS issue at:
http://weblogs.asp.net/larryosterman/archive/2004/08/12/213681.aspx

Long story short: Windows relied on and modified a lot of the data structures in MSDos.  Any Dos clone would need to be a Perfect clone or Windows would fail.  So requiring MSDos made sense.  Their mistake was trying to hide that fact instead of being open about it.  Too bad they didn't have Channel 9 back then.