Are they compatible? 
ZBrush is not officially supported on Windows 7 at this time. That being said, I’m only familiar with one potential issue, which is that someone has reported not being able to get above 20 or 30 ZSpheres on a model.
aurick,
will the problems be figured out by the time zbrush 4 is released?
thanks,
Paul
The problem with ZSpheres flying off into the corner has already been fixed on the Mac. This crashing issue is most likely related to that, and so is probably already fixed. But we’ll keep an eye on it with Windows 7 as we get close to release.
I did a little testing over the last couple of days with Windows 7 build 7100 RC1 and Zbrush as well as 3dsMax 2009.
I would like to report that Zbrush has not failed once… zapplink tested, level 6 Subdivision on several models and sculpted beautifully.
Wacom Tablet working as intended as well.
Admittedly did not test any zspheres.
3dsmax , working good, encountered once issue when using 12 materials that all were 4096x4096 resolution and had them all enabled to display on mesh in viewport… would cause any attempt to add another material… even a bump map of 1024x1024 to cause an Image I/O error when attempting to add it.
This i think is more of a memory tweak issue then a bug from windows 7 however as I used to get the same thing when when I was running an underpowered P4 with only 2 gig ram.
win7 is shaping up to be geat. and… well Zbrush is already great!