Backwards Compatibility - Windows 8 Apps compatible with Windows 7?

Question

I am finally getting ready to install Window 8 on my second drive. Yeah I know, as far as this community goes, I am late.

[ I hope this is the right board to post this ]

I have done some searching on the matter of , "Will apps developed on Windows 8 be compatible with Windows 7?"

Some say yes, some say no and some say "Well it all depends".

I think the answer, "Well it all depends" most likely fits the bill correctly, but what are the stipulations that would constraint an application to Windows 8?

If I wanted to create an application in the Windows 8 environment using VS Pro 2012, what should I avoid in my application to ensure it will run on Windows 7 as well.

What about using VS Pro 2010 in the Windows 8 environment , would that ensure the application will run on Windows 7?

I think this is extremely important being as though we all know that many people will wait a long time before upgrading to Windows and some will even skip it and refuse for as long as they possibly can.

Answer 1

Windows Store Apps run on Windows 8.  Windows desktop apps that run on Windows 7 also run on Windows 8.  You can develop on Windows 7 and then run on the Windows 8 desktop for x64 and x86.  For the most part you can develop a desktop app on Windows 8 using the appropriate version of Visual Studio 2012 however the inclusion of WinRT APIs would make it not work on Windows 7. 

Answer 2

So it would be primarily the WinRT API that I would need to avoid in order to make sure the application will run on Win 7 and Win 8?

Answer 3

Correct.  There are also updates to the Win32 API for Windows 8.  You would need to avoid those as well or wrap them in code to fall back to the Windows 7 equivalent (if it exists).

Answer 4

[ Hope I am not making this more difficult than what it really has to be ]

So say I create an application where I only reference the most current .net framework ( I understand that at some point, even the .net framework will out grow Win7) , should I be good to go? I want to make sure I understand fully before I decide to move completely to Windows 8, for now I am just going to dual boot and mainly work from Windows 7 then cross test from there.

Thank you for your persistent responses Eric. 

Answer 5

Note that the Tailoring your Windows Store app for hardware and devices forum you are posting in is specific to writing Windows Store apps, which run only on Windows 8 and Windows RT.

Questions about writing desktop apps in native code should be posted to the Windows Desktop Development forums and questions about writing managed code to the .Net Framework forums.

That said, if you use the .Net Framework to write a desktop app you should be able to run in Windows 7 and in Windows 8 without any significant worries. For native apps you can configure the headers to contain only the functions available on a specific OS. See Using the Windows Headers. ]

Obviously, if you want to use any OS specific features you will need to gracefully handle their absence on other OSes.

--Rob