Yes. Windows is extremely backwards compatible. This could be, ironically, one of the reasons some people don't like it too much. See Raymond Chen's The Old New Thing [1] for some technical details.

[1] http://ptgmedia.pearsoncmg.com/images/9780321440303/samplech...

The latest Windows update won't install for me. It pops up an error saying "Uninstall this app now. It is not compatible with Windows 10."

Yes, it says "now," in command form. And the app, VirtualBox, works just fine in Windows 10.

Doesn't seem very backwards compatible these days.

If the program manifest doesn't advertize compatibility with the current version of the system, its window will be scaled.

Since when do windows break most programs every few months? Having to write a patch every few years when Microsoft releases a new OS is pretty low maintenance. And most of the time windows is backwards compatible nowadays, so usually you don't even need to do that.

Most 10 year old games still runs on modern windows even without patches etc.