Hi,
Interestingly the nvidia detector doesn't detect the card now either, will try removal/reseating later.
I can assume .. if the card is not well seated .. your monitor will have no signal and will appear a error message on the screen "No Signal .. blah blah"
I take for granted as the drivers you are trying to install are for your card and your OS.
Also try in the device manager to delete the hardware entry for your graphic .. save and restart your PC.
OS will detect the card at start (usually) ..but you must refuse the OS to install drivers if proposed and after you can install yours.
Hope it's help.