versions of windows

[paneInTheWindow]

Having a good basic understanding of operating systems and programming I have a rather simple question,

reguarding why some programs require a more modern version of windows, like applications that require win98 for example, and will not work with 95.

Applications are designed for a specific operating system, on a fundamental level the application ultimately consists of OS function calls(API) function calls,

which inturn invoke bios functions or device drivers to communicate with system devices. For example DOS applications consist of dos function calls, which in turn

call bios routines, a driver of sorts, to communicate with the hardware device and make it do what its supposed to do. It is understandable why a windows 95

application would not run on a pure dos machine because the dos machine among other things does not have a definition for the function calls that are

used in that win95 program. Conversly, backward compatibility dictates that as new programming standards (OS function calls) are added, the old os function calls

must be preserved, so a dos application would run on a win98 machine. My question is, do these applications that demand win98 make OS function calls

that the dll files native to win95 do not define, or is it that microsoft wants to force you to upgrade so the program checks the local registry to see what the

value is for the operating system and if its not 98 the program simply terminates. Furthermore, assuming if the program demanding win98 to run is function call

compatible with 95, could you just modify the os version registry key value to 98 and have the program run in 95. Furthermore if this is not the issue at all,

could it be a matter of the dlls that define windows function calls needing to be updated. In other words add or replace dlls that define function calls and then the program

that once demmanded 98 will work just fine with 95 with modified os version regisrty keys and or updated dlls.

-Andrew

[scuzzman]

As spaghetti-coded as Microsoft's software is, they do re-write the kernels with every OS. It's not just a matter of the API's, or just the DLL's for that matter, or even just the kernel, it's a matter of all 3 and how they interract.

In theory, yes, you could simply replace the DLL files and the kernel, and the registry and etc... but then you'd just be replacing the OS.