8800GT - install issues and no control panel

When I tried to install 7 ultimate, it would always hang at "starting windows". I got past that by removing my 8800GT video card and plugging into my motherboards VGA out. I then installed the latest Nvidia drivers (8.17.11.9562), shut down, reinstalled my vid card and then could boot into windows. Now device manager shows my 8800GT and shows the right driver, but control panel won't start and it says "you are not currently using a display attached to an Nvidia GPU". I have reinstalled the driver several times with no luck. I have also run driver sweeper but when I did that I had to remove my card again and go back to the motherboard VGA out to get my system to boot. My card seems to be running in VGA mode or something. I cannot load any games and without the Nvidia control panel I can't set up Dualview for my second monitor. I have searched high and low for a solution to this but no luck.

is this a fresh install of windows 7, have u had problems with this video card before, are u sure your 8800gt is not overheating, have u owned a ati card before u install the nvidia card

Thanks for the speedy replies guys. Yes, this is a fresh install on a brand new drive, not an upgrade. There was never an ATI card installed. This card worked flawlessly 5 days ago under Windows XP. It's definitely not a heat issue. I've also now tried the newest beta drivers and got the same result.
I haven't checked my bios yet (I've never seen the setting you talk about), but I will check in a moment.

I have physically removed and reinstalled the card several times so it is definitely not a seating issue. Device manager shows the card by name and lists the current drivers but when I try and run Nvidia control panel it says "you are not currently using a display attached to an Nvidia GPU".

if u look at my specs i have two 8800gt, with both systems running windows 7 just fine, im pretty sure whats going on u need to run drive cleaner u can find it at guru3d.com in the download section, also go to my computer delete the nvidia folder, along with the registry after u run drive cleaner, find Hkey_current_user/software/ delete anything thats nvidia, again the same thing hkey_local_machine/software/ there should be two folders nvidia then in wow6432node, after that go into safe mode run drive cleaner once more, then reboot install drivers, and last the best drivers ive found that worked that best with 8800gt cards is 191.07 download it at guru3d good luck