Edit: In searching for a possible solution, I ended up just quoting something from the first page of this thread. So - no doubt you've tried this. Apologies! Note to self - don't respond from cell phone lol
I found this suggestion, but have no idea if it works. I think it's worth a shot - please let me know if it works.
For Unsupported Card [2001]
go to: C:\Program Files (x86)\Origin Games\Simcity\SimCityData\Config
Save a copy of ConfigManager.txt to somewhere you can find it, such as your desktop.
Go back to the Config folder & open ConfigManager.txt in notepad. It will look like the text below this message.
Find the part near the bottom that says
"set DefinitelyFail -3"
and change it to read
"set DefinitelyFail 2"
Save the file, close it and try to launch SimCity.
If it gives you an error, you can just replace the changed file with the copy of the original
# Configuration rules and options for SimCity
#
# This script both defines what the various game options
# do, and sets defaults for them based on the video
# card, sound card, CPU, and other factors.
#
# It also sets some properties determining what the
# hardware will support.
#
#############################################################################
# Constants
#
set Off 0
set On 1
set Min 0
set Low 1
set Medium 2
set High 3
set Ultra 4
set ModernFail -1
set ProbablyFail -2
set DefinitelyFail -3
# Shader paths -- must match with Material/config.mtl
seti shaderPathMin 0 # Not well supported
seti shaderPathLow 1
seti shaderPathRecommended 2
seti shaderPathMax 3
#############################################################################