Display driver problem

I saw a display driver update listed on my windows update for my PC I downloaded it and installed it.......then my screen went blank! Nothing at all just a blank screen. I rebooted and still the blank screen. I rebooted into safe mode and checked in device manager and my display device had a yellow triangle with exclamation mark showing there was a problem. I was going to use the rollback feature to rollback to my old driver but the option wasn't available to use. I went into control panel add/remove programs and removed the NVIDIA drivers. I rebooted my machine and i could see the screen ok...everything was fine.....BUT a window opened giving me an option to reboot now to install NVIDIA GeForce 8400GS properly or wait till later, i chose now and ended up with the same scenario as before......Nothing on my screen after the pc had rebooted. I un-installed the NVidia drivers in safe mode...rebooted to get to where i am now.....I know that when i turn this pc off i will have a blank screen again when i boot up and will have to go into safemode again to un-install the driver....then boot back into normal start up in order to see my screen....Can someone please advise me how to get things back to normal.....I have windows Vista home premium with service pack1. Thanks


Scots-Nat