The title's got it in one. Used to be able to run Wizardry 8 fairly easily. Ended up having to delete it at some point to make room for other games, back before i upgraded the memory.

Now that I've tried reinstalling it since I actually have space now, it won't run. I've tried running it in Compatibility Mode for Windows 7 and 8, I've tried messing with the settings, verifying/repairing it, I've even tried running it as an Administrator. Same thing keeps happening. The play button on GOG goes dark, and then lights back up. Game doesnt even appear in the Task Manager.

I'm going to assume that this is a common occurrence on things like Win 10 and Win 11. Anyone have any suggestions or advice?

Get a better computer, re-download from GOG.com?

Last thing you need is a new comp
min system requirements are iirc in the region of 64MB Ram, 300MHz CPU and 16MB Graphics.
High fps may even be counterproductive at certain spots.

Assuming install is correct, navigate to the games folder Wiz8InstallDir\data\flics.
Inside you see the folder "intro" containing some .bik files. Rename that folder as you like, e.g. to "Intru",
and check if the game runs now. If so you will not be able see the intro cutscenes,
bc newer win versions dont support the codec, but the game itself should run fine.

Also make sure the game is not installed in an UAC protected folder like program files (x86),
athough that does not prevent it from running at all.

I've got it on GOG. And my computer's only a few years old. Tried changing the intro file. Unfortunately, it didn't help.

At this point, you can run W8 on a potato.

Go to Best Buy, buy a mid-ranged computer that is configured for average gaming (probably $500-1K). You mangled your last computer, so buy a new one. This isn't rocket science.