You should never run anything in a compatibility mode.
I've just done a fresh install of SH3. I backed up the game incase.
I downloaded and run the 4gb patch.
Installed GWX, looks like its running.
** SH3 runs fine, making sure to do the first mission as default, otherwise the game will crash. Other than that working, thank you.
You may need to do this as well
https://steamcommunity.com/app/15210...3594739326655/