Let's install an unsupported NVIDIA GeForce 7xxx PCI-E GPU in Windows 98!

In this video, I'll show you how to get nVidia 6000 or 7000 series graphics cards working on Windows 98 Second Edition. This method should also work for Windows 95, Windows 98 FE, and Windows Millennium Edition.

Driver link: https://theretroweb.com/drivers/96
Patches link: https://archive.org/details/PTCHNVSZ

Quick summary:

First, we start by patching the nVidia driver 'nvcore.vxd' using ptchnvc.exe.
Next, we patch the WINDOWS/SYSTEM/PCI.VXD file with ptchopt.exe.
We then check for the EOI bug using TESTEOI.VXD. If it's present, add the following line to SYSTEM.INI: [386Enh] DEVICE=FIXINTR.VXD (the .vxd file must be placed in the Windows/System directory).
Lastly, if needed, we can patch the GPU's BIOS itself by flashing it using ptchnvsz.exe."