Hi EA_Illium
File integrity is ok. I also did "Repair" in Steam. So it should be fine. I updated the system, as well as the processor and BIOS. The drivers for the RX 470 are also the latest ones downloaded from the manufacturer's website. I haven't checked from a brand new admin account yet.
But there is one but. As I mentioned, the DEMO version works. I compared the files in the folders and they are identical. I started converting files from the DEMO version to the FULL version. That didn't help either. The game still seems to start, but in fact the Launcher comes back again.
I decided to delete all files from the Need for Speed directory. I deleted it. I copied the contents from the DEMO version directory to the FULL version directory. I went back to Launcher. It showed me the DOWNLOAD option. So I clicked. And surprisingly, the game started. I pressed SHIFT + F1 and it says NEED FOR SPEED DELUXE VERSION at the top. And it would be nice because the full version would run for me. But during launch, the STEAM_APPID.TXT file appears in the game directory. The button in the Launcher has changed from DOWNLOAD to PLAY. And when I restart the game, the 8-hour DEMO version starts.
I know I'm tampering with the game files, but every time I delete the contents of the full version from the directory and paste the contents from the demo version, I am able to run my full version when DELUXE EDITION. This is strange.