
Turns out I actually do link propsys.lib

so I can use the PSFormatForDisplay function. Although the API help states Windows Vista to be the minimum supported OS I am actually very positive that the plugin runs just fine on my Windows XP machine

Maybe because I installed WDS 3.0 separately. Or maybe because I have Visual Studio and Platform SDK installed.
Sorry to anyone who tried to find a solution to this problem

. And thanks to ecaradec for the hint

.
So I guess my current solution is to make Windows Vista the minimum supported OS for this plugin.
(I think I have never used so many smilies in one post)