I don't think it is a conflict. Because I ran geany on 3 computer, with windows 7 x64, windows 8.1 x64, windows 10 x64, and got the same result.
I wonder if it's something you are running on each computer though. A lot of people use Geany on all those platforms (myself with existing and clean installs on win7 and win10) without this issue, though I'm not sure what's causing your problem.