GPU Fan Speed Fixed at 65%

I have an NVIDEA Geforce 7600GT (I know it is old but it came in a computer someone gave me). When the card was installed in the old computer (Dell Optiplex 380, Windows 7 Pro 64 bit), you could hear the fan spin up to maximum for 5 seconds or so when the computer first was turned on. I don't hear that now when the card is in my Windows 8 Pro 32 bit computer (FX 6300, Gigabyte GA-78LMT-S2P). I am running 2 21inch monitors using DVI-D connections on the GPU. GPU was installed in this computer about 3 months ago.

For the past couple of days, the screens would go black for a few seconds and then come back on. I would get the message "Display Driver Has Stopped Responding and Has Recovered", so I decided to re-install the latest drivers (Yes, they updated the drivers as recently as 2015). So far it has been about 3 hours and no more black screens.

I thought maybe I was getting thermal throttling so I fired up GPU-Z and I was at about 54 C. When I watch recorded TV or a DVD it goes up to 60-61 C and stays there. GPU load is 60-64%. Fan speed is a constant 65%, no matter the temperature.

Ran Furmark for about 3 minutes and the temp slowly went up to around 80 C so I shut Furmark down, not knowing if I was getting close to the limit. Fan stayed at 65%.

In the NVIDEA control panel, there is no setting for fan speed. Airflow is not an issue, as I don't have any other cards installed and the side of the case is currently off.

I would like to be able to set a fan profile, or simply increase the fan speed to a higher constant, but can't seem to find a way to do it. I read through several other threads, but didn't see any sure-fire solutions.

Any ideas?
 
Thanks Ranger. I downloaded MSI Afterburner, and it looks like it will do the trick for me. Under load, changing the fan speed from the minimum 30% to 100% only affects the GPU temp by a couple of degrees C. The fan on that GPU is quite small, and probably doesn't move much air. Luckily I don't use this computer for gaming, so temperatures shouldn't be a problem.