JohnnyBoy, 11GB free on your C: drive, where I assume ZBrush3 is installed, is probably not enough for the virtual memory paging ZBrush does. Especially if your drive is fragmented.
Also please try the AMD Dual Core Optimizer instructions I gave for vine.
AnneLise, would it be better to free up another 10GB on my C drive, or to reinstall zbrush on my other hard drive with over 400GB free?
I would install it on the other drive. You can’t have too much space when dealing with multi-million poly files. 
Ok, I freed up about 30GB, defragmented and ran the dual core optimizer. So far, so good.
This may be good enough until I get a new pc over the winter. I did notice that it now quickly skips past the intro screen where you choose what you want to do.
Anyway, thanks for the advice.
sorry for my bad english…
well i had the same problem, and i find a solution for the moment… uninstall zbrush, remove all the plugins / scripts / etc. , install it and use it as default…
mmm i had power of 2 and zapplink 3 only installed… maybe zapplink is the problem… zbrush works fine for me now…
Hi,
The same thing is happening to me. Here are the specs for my machine:
Single Dual Core AMD Athlon 64 X2 4200+ 2.2 GHz
Asus A8N-SLI Deluxe
4 Gbs Ram
It was running on this machine and this never happened:
Dual Single AMD Opteron 246 (DP) 2 GHz
Tyan S2891
4 Gbs Ram
Could this possibly be a hardware issue with the AMD processors? Just a hunch.
Thanks
Try disabling DEP for ZBrush. (Data Execution Protection) Doing a Google search will turn up the instructions you need for how to do this.
badgirl, what specifically is your problem. There is a known save crash problem, but may be fixable using one or both of: adding ZBrush3 to data execution prevention and/or use of the AMD core optimizer.
I forgot to say I’m running Windows XP x64 SP1. But, I switched DEB from “Turn on DEP for essential Windows programs and services only” to “Turn on DEP for all programs and services except those I select” and excluded Zbrush. I was able to open it and close it multiple times without it crashing. Hopefully, this will continue to work. Thanks!
hi, i am also running 3.1 on XP, on AMD 64 X2 3800+. Zbrush is crashing around once every ten mins with a particular option, whicih is when i am jumping around on the subtools, from one to another smoothing or anything else to that matter. It has done it plenty whilst changing material variables and then re-rendering and re-rendering. The system seems to become overwhelmed with what its processing in repetition. (use to have a simular problem on the mac with Z2)
This is a new system, windows XP, complete clean install. Only Zbrush 3.1 has been installed. 2gigs of ram, with Zbrush mem settings as suggested above. The HD has plenty of space, around 75gigs.
I have tried the download from the AMD site as recomended above and it kept crashing even sooner so i unintalled that. I do keep an eye on the mem counter at the top and that has always got over a gig when it crashes.
It doesnt normally crash in sculpting operations themselves, so no poly adjusting seems to set it off. Narrowed down to function swapping such as material changes and then re-rendering over and over and tool swapping in subtools.
I noticed one issue, you could call it a incompability issue that causes Zbrush 3.1 to bail out and instantly crash upon startup. This happens if you have installed Sysinternals Process Explorer and if it’s open. Then Zbrush 3.1 refuses to start no matter what you try… but closing Process Explorer will let Zbrush start again. This happens on my XP64 system with 8gb ram. I don’t know yet if this also happens on XP32 but most likely it will happen.
/ Max
Zbrush 3.1 used to crash on me since i upgraded my pc ( don’t ask me why ) but disabling DEP solved the problem or at least since this morning i haven’t had any crash with the same ZTL file that used to frustrate me ( crashing after 10 to 20 seconds of loading ) so thank you for pointing that out … the DEP disabling saved me really, thanks AnneLise and aurick 
good luck with the others
my system spec in case it might help :-
Intel Pentium D 3.40 GHz 2x2 4mb cache
ASRock 4Core1333-eSATA2 motherboard
4 GBytes DDR2 667 bus
Nividia GeForce 8500GT DDR2 1024 MB
320 GB SATA2 hard disk
Microsoft Windows XP Professional x64 SP2
alright … sorry to say this… crashing is back and i am getting spikes kind of effect when i switch between different subdevisions, when i am not crashing, the model is only 19844 polys at its max subd 4 while Zbrush compact mem is 2 GB, and MaxPolyPerMesh is set to 20 … i have 35 GB free disk space on C: where zbrush installed… any help ? suggestions ? … aurick !!!
I have very similar specs and I solved the problem with a solution I used for
a different program but with similar problems.
For me it was an affinity problem, dual core processors have an affinity with 2 cores,
to solve the problem you must set the affinity to one core.
You go to Processes, the ZBrush process will just be ‘healthy’ for a short amount of time (due to the early crash), so it’s best to use inversed alphabetical order (so the Z processes show up first).
@Max the Artist
Had the exact same startup issue described in this thread (on Intel Duo CPU and non-NVIDIA hardware) and your solution solved my problem. Closing process explorer and all is well again. Thanks for posting this!!
nozem’s solution worked for me! Thank you!
Slightly different symptoms, mine crashes just as the Loading Zbrush splash starts to fade. Then about 1 time in 10 it will actually launch.
But installing the AMD Dual Core Optimizer seems to have helped. Now it launches and so far (crossed fingers) it’s happy.
Helped for my 32bit XP SP2, (on Intel Core2Duo CPU and NVIDIA).
Thanx
What if I compress my C: drive to have more space? Does it effect working of 3D software? Has anyone tested it ?
Compressing your boot drive will make your computer slow. Slow as in glacial slow. A tera-byte sized hard drive costs $79 at NewEgg.