Must say that the manner in which Windows 10 (installation/upgrade) pop ups appear on older versions of Windows is rather odd.
That said, the manner in which MS chooses to address certain issues [0] is rather weird. (Not sure if this one applies to Windows 10 too, does apply to Windows 8.)
And then you can "Run Bash on Ubuntu on Windows" [1]. I fail to understand how different is it from running Cygwin or MSYS/MinGW if you can't interact with Windows applications.
That said, the manner in which MS chooses to address certain issues [0] is rather weird. (Not sure if this one applies to Windows 10 too, does apply to Windows 8.)
And then you can "Run Bash on Ubuntu on Windows" [1]. I fail to understand how different is it from running Cygwin or MSYS/MinGW if you can't interact with Windows applications.
[0] https://support.microsoft.com/en-us/kb/3053711
[1] https://msdn.microsoft.com/en-us/commandline/wsl/about