During boot the apps that set fan speed haven't started so default is full speed.
But here's the thing. 8800 video cards are dropping dead now. Who's to say this card has not failed?
I probably completely mangled that subject line, but here's my problem. I have a Dell XPS 630i with an NVIDIA GeForce 8800GT. If I try and play games on it, the card's fans spins up. This is good. What isn't good is that if I close my game/whatever spins up the fan, and I don't give the fan time to cool the card and spin down, the card fan will run full blast after I start the computer back up until it arbitrarily decides to spin down. Has anybody else had this problem? Or found a solution. This problem did not happen on Windows XP, but it only started after I upgraded to 8.1 in March 2014 for obvious reasons. This problem also occured when I briefly upgraded to Windows 10, and continued after downgrading back to 8.1 due to a string of Video TDR BSODs.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic