Even if the bug wasn't in our code, it was really helpful to see what's going on inside, helped us figure out why something didn't work a lot of time. Making false assumptions, passing stuff in a different format than the system expects etc.
We all, always worked with a decompiler in eclipse, just because it really did make life so much easier sometimes. And well, of course, sometimes there really was a bug in the stack, and finding a workaround is much easier when you know what's going on.
If Windows was good and near-bug-free, Wine would have long been completed. Windows is not just its kernel.
And of course Wine is an outlier. Not only in that it contains its own 20 years of legacy code but in the fact that it is black box reverse engineering. It can't use disassembly to suss out details. Wine's difficulties stem from its requirements as much as anything else. These days VM's are the way to go if the going is intended to get things done. A Windows box in the cloud is pennies per hour.
Here's a link from 2008 that shows how it works:
http://blogs.msdn.com/b/sburke/archive/2008/01/16/configurin...
