Any idea how much code in Windows in order to be backwards compatible

[Mark R]

I came across the following, rather old, blog entry a few days ago:

A certain software company decided that it was too hard to take the coordinates of the NM_DBLCLK notification and hit-test it against the treeview to see what was double-clicked. So instead, they take the address of the NMHDR structure passed to the notification, add 60 to it, and dereference a DWORD at that address. If it's zero, they do one thing, and if it's nonzero they do some other thing.

I got tagged to investigate and fix this. I had to create a special NMHDR structure that "looked like" the stack the program wanted to see and pass that special "fake stack".

So, rather than ask the publisher of the application to fix their totally screwed up programming - Microsoft had to deploy engineers to find out why this software didn't work on 2k/XP, and then had to modify Windows so that this program could continue to run.

Admittedly, it makes reasonable business sense for MS to do this - but at what technical cost?

Cliffs:
1) Dodgy software company writes popular business app
2) Their programming sucks big donkey balls
3) App doesn't work on 2k/XP
4) Software can't supply updates to fix problem
5) Microsoft modifies Windows so dodgy program can continue to work.

 

[Smilin]

There is a process available to Microsoft premier customers whereby they can as for Critical (Fast patch before next release) or noncritical changes to how Windows behaves.

Factors that contribute to the request being approved or not:
business need,
availability of workarounds,
impact to others,
age of product in question (XP more likely than 2000 pro for instance).

In the example you listed the availability of workarounds is low so that would help. The fact that the customer (or app vendor) is doing something retarded would really hurt the chances of a change getting approved.

You would probably be surprised how often MS changes things to make customers happy. People think because MS has a monopoly it doesn't have to listen to it's customers...the opposite is true. You won't stay a monopoly by being inflexible or ignoring your customers.


The above is a very, very loose overview of things - I don't run a disclaimer often but in this case: 1) I am not speaking in any official capacity as an employee of Microsoft. 2) I might just make sh1t up to keep you on your toes.