Good for you trying to be honest.
If the cooler was scorching hot then it had a great contact with the core, but it shows there wasn't enough airflow onto the heatsink to remove that heat. Perhaps the crash that occured when it overheated (I thought Nvidia cards had thermal protection anyway?) corrupted the drivers- I'm surprised the BIOS looks OK. If you try the card in your other machine, try a Linux bootable distro to see if it works, if you can get one with Beryl or Compiz on it that will stress the 3D aspect of the card.
Or, try Driver Cleaning your Windows system and rreinstall drivers.
If the cooler was scorching hot then it had a great contact with the core, but it shows there wasn't enough airflow onto the heatsink to remove that heat. Perhaps the crash that occured when it overheated (I thought Nvidia cards had thermal protection anyway?) corrupted the drivers- I'm surprised the BIOS looks OK. If you try the card in your other machine, try a Linux bootable distro to see if it works, if you can get one with Beryl or Compiz on it that will stress the 3D aspect of the card.
Or, try Driver Cleaning your Windows system and rreinstall drivers.