Which version of Windows do you use? in Grand Theory of Everything Posted April 6, 2010 · Report reply I agree with Rick on keeping an XP-compatible version of PDN out for a while after mainstream support has been dropped. If you look at the usage statistics, over half of all PDN users are running XP! But with Windows 7 having been released & it's adoption rate being so high, the odds are likely that those numbers will soon change. And for all windows users reading this post, I implore you, upgrade to Windows 7 if you haven't already! It's awesome & well worth it. Anyway, vista+ is the way to go for v4.0. We all know how many PDN users would love to see brushes as a feature!