Ran into the same problem with older Nvidia chipsets at my office. If you're feeling brave... here's a way around it: Install Win10 using the media creation tool. This will bypass the compatibility check. Once you boot into Win10 for the first time, it will be using the default display driver at 1024x768 resolution. Then, install the last Win8.1 driver available for your video chipset. It should work and get you back to a reasonable resolution.
Please note that this is mostly for business users who aren't worried about 3-D and whose video cards are end-of-life (meaning they won't be supported in the future). Doing this will force DirectX back to a compatibility mode for whatever DX variant your driver supports. For instance, on my Geforce 6150SE systems at my office, dxdiag now reports WDDM 1.0 instead of 2.0... and is running DX9ex compatibility instead of DX12. So do it at your own risk... but it's totally working fine for several of my business machines so far. It's a shame that AMD and Nvidia aren't providing at least a basic driver for these older chipsets, considering how recently they were used in basic business machines.