i did a search on the forums and didnt find a thread like this and i know i need to contact support BUT…
I bought a Mac version of 2.0 with a promised upgrade to 3.0. 3.0 came out Intel only, i couldnt get the upgrade NOW i bought a PC with Graphics capabilities that rock! Can i get the upgrade now for the PC version? Anyone done this? Am i too late to do the upgrade?
jake angell
yes we are to late. the offer ended once z3 for mac was released.
I had the same question just a couple of months ago.
you can buy a crossgrade for a reduced price. this would make you a happy owner of a licenced mac version and a win version.
volker
yeah, that sucks…thanks for the info.
I want to THANK everyone on the Pixologic Support site that worked on my ticket quickly and with all courtesy when I sent it in. PLEASE PLEASE make sure they hear this!! 
My faith in ZBrush is restored…i am about to cry…i loaded up the copy of ZBrush on my PC…snif, snif! I hope I can make you PROUD of me Z…!!
I bought a PC but still have an Apple…50/50 on either now. Lightwave on the Mac and Zbrush on the PC.
I’ve been a lot happier with ZB on a PC (Vista x64.) I found the ZB support guys most accommodating during my transition from Mac ZB.
-K