#3306 doc: mention Windows 8.1

Signed-off-by: Patrizio Bekerle <patrizio@bekerle.com>

Author: pbek

webpage/src/installation/windows.md

@@ -23,10 +23,11 @@ You don't need the portable mode if you just don't have Administration permissio
 to your computer. QOwnNotes doesn't need to be installed!
 :::
 
-## Windows XP
+## Windows 8.1 and older
 
 Qt dropped support for Windows XP with version 5.8, but QOwnNotes is now also built
-with Qt 5.7 to allow Windows XP users to still use it.
+with Qt 5.7 to allow Windows XP users to still use it. Windows 8.1 has issues with
+the regular QOwnNotes build, because it was built on a newer Windows SDK.
 
 You need to download the ZIP file from [AppVeyor](https://ci.appveyor.com/project/pbek/qownnotes/build/artifacts)
 yourself and unzip it to a folder of your liking.