My company has a desktop app originally developed for Windows XP. The original programmer has since been fired (fired with extreme prejudice I might add). I have fixed the app various times but overall try to avoid it, it is a mess and the only real way to fix it is to completely rewrite it, which could take a year.

We have been trying to "forget" about this app, and instead steer clients towards our web version, which is more up to date, easier to maintain, easier to extend, and WAY easier to support. Most clients agree, the web version is just better all around.

However we have one client that insists on using the desktop app. The app required a little duct tape to get working on Vista, but now completely breaks on Windows 7. I'm not even sure WHAT all the fixes are to get it working on Win7 (the current time estimate stands at "miracle") but after both installing the RELEASE build, and running the DEBUG build from Visual Studio, the app has errors on nearly every user action, and from what I can see from a high level test run, none of them are related.

Since Windows 7 did not exist when this app was developed, is my company really expected to make all the required changes to make it function as "smoothly" as it did on XP?