When I run the game, nothing happens at all. If I check the task manager, wiz8.exe starts briefly, then closes after a few seconds.

This is Windows 7 x64.

There is a Windows Application Log corresponding to the time I try to run Wiz8. First an Error:
Faulting application name: Wiz8.exe, version: 0.0.0.0, time stamp: 0x3c26eee6
Faulting module name: Wiz8.exe, version: 0.0.0.0, time stamp: 0x3c26eee6
Exception code: 0xc0000005
Fault offset: 0x0000004c
Faulting process id: 0xf6c
Faulting application start time: 0x01cfa94451f07c85
Faulting application path: C:\GOG Games\Wizardry 8\Wiz8.exe
Faulting module path: C:\GOG Games\Wizardry 8\Wiz8.exe
Report Id: 8fa9c16e-1537-11e4-89f3-e070daf0578a

Then an Information:
Fault bucket 1501377927, type 1
Event Name: APPCRASH
Response: Not available
Cab Id: 0

Problem signature:
P1: Wiz8.exe
P2: 0.0.0.0
P3: 3c26eee6
P4: Wiz8.exe
P5: 0.0.0.0
P6: 3c26eee6
P7: c0000005
P8: 0000004c
P9:
P10:

I found this fix:
http://www.gog.com/support/wizardry_8/wizardry_8_does_not_launch

but it did not seem to make a difference.

That error says the path is C:\GOG Games\Wizardry 8\Wiz8.exe… is that in fact where you installed it?

Yes. I actually installed it to f:\wiz8 the first time, and when I couldn't get that to work, I tried a total uninstall, and reinstalled it to the default location for troubleshooting purposes.

I just discovered something interesting.

I renamed the folder "Wizardry 8" to "zardry 8." The full path is now:
C:\GOG Games\zardry 8\wiz8.exe

And now it works. I tried renaming it to "izardry 8" and then it didn't work again.

So it seems like it crashes silently if the full path is more than 30 characters long? This seems like an oddly specific crash bug. Also, it works fine on my laptop, even with the default path.

I got it to work, but I am still curious to know why this particular behavior is occurring, and what I can do to stop it. I have a particular file directory structure that I use for gaming, so I can't really consider this problem solved until I can get Wiz8 to work in the directory I prefer to install it to.

I have exactly the same problem, but my file path wasn't as long (tried even shortening it to just F:\GOG\Wiz8\ but it made no difference). No matter what settings I try, what configurations I choose from the setup, Wiz8 just will not lauch. I submitted a ticket to GOG, if I receive a solution that works, I'll post it here.

If anyone comes here and tries all the stuff with no luck I was the same.

I moved the Wizardry 8 folder to the root of the C drive and renamed the folder to "8" so the full path is C:\8\Wiz8 and it booted immediately.