So, I had a play with it... managed to get the bitcoin-qt.exe in Windows Explorer showing the modified icon:
However, within the app it is still showing the original
To get the custom icon showing... I actually had to manually delete all the *.o (object files) in the "bitcoin/src/qt/" and "bitcoin/src/qt/res" directories and then use
makeIt seems that just changing the .ico file etc was not enough to trigger a proper recompilation. So, I'm guessing, if you have already made the project, then tried to change the icons, that it will indeed be using the "old" resources.
And finally... I managed to get the "in app" icon changed:
This is defined by the bitcoin/src/qt/res/icons/bitcoin.png file
Again, I had to:
in both of the following directories:
bitcoin/src/qt/res
bitcoin/src/qt
Then from "bitcoin/src" run
make as normal...