In my installation I have a third party un versioned exe file that I needed to replace with a new version. Simply checking the "Overwrite Any Existing File" did nothing, it left the old version of the file, so I had to delete the existing file and add a new one. It did work, but...
Any subsequent Quick Patch would remove the new file and left my installation without it.
As a patch is just another way of delivering a Minor Upgrade, we have to abide by the Minor Upgrade rules. If the file you are replacing is a key file, make sure that it has the same name - as Minor Upgrades don't support the removal of Key Files.
Also, in a quick patch project there is check box for "Include Whole File" - Non-versioned files will always be overwritten when this option is selected.
