Why does my video card go back to stock fan speed?

Ok , please don't look at the question and just answer that.



There are a number of issues i need help with.



First of all , i was basically normally browsing the internet and noticed my fan speed was set to 80% it went back to 50% , so i had a look at rivatuners options and noticed when i set it back to 80% it kept resulting back to 60% ....



My psu is a 500w Ocz. More than sufficient for my 9600gt 512mb.



I noticed a high amount of lag on call of duty 4 , i cant quite figure out why im lagging because my cpu is more than enough for the game , same with my 2gb's of ram and my gpu.



Now i came up with to conclusions :



Dust?

Video Drivers?



So with that being said , i disconnected all power leads from the computer , and began to clear the video card for dust. The psu is brand new , so im not considering that to be faulty. Once i had cleaned the card for dust , i then took out a fan that was planted underneath my card to give it some extra cooling. It could of been screwing up the airflow as it was directly under the video card fan.



Im yet to try new drivers , but i don't want to update to newer ones , so if possible could someone point me in the direction of some custom older drivers for my card?



So what do you all think?



Call of duty 4 is fine tuned for lower pc performance , all tweaks applied are put into a CFG file that are placed in the call of duty 4 main folder. Example? r_gpusync 0 simple commands like that , just encase you wondered.|||is ur psu brand new? it might not be supplying enough power to fan so try tuning rivatuner for more power output. if that fails, check the hard drive in case youve used up too much free space.|||Could be your CMOS battery is dead on your motherboard which means any settings you make to your BIOS will revert when you restart your computer...I assume this will include changes made with rivatuner. Don't know where you get the idea that your power supply is not faulty because it's brand new. A number of items are "DOA"...not necessarily in the sense it's dead on arrival, but more so defective on arrival. It may work, but is defective in some way. That being said, I don't believe it's your power supply, I'd think it's actually your graphics card first...not that it might not've been caused by your new PSU being faulty. I would try new drivers first to see if they work...if they don't fix the problem and you find you don't like the new drivers, you can just revert to your old ones...no big deal. Can't really think of anything else though...with computers it really can be a number of things, but it honestly sounds like your GPU may be going. How old is your motherboard exactly? And have you EVER overclocked your GPU, or have you recently been using it strenuously...playing graphic intense games and such for long periods of time? Any part of your computer can go at ANY time, without warning, or arrive faulty. A recent hard drive I purchased was actually faulty, but not at first glance. It's wasn't really a noticeable fault per say, but it was there, and even though I was able to install the OS and use the drive, it did have a fault...some error with managing RAM...and I got it RMA'd and the new one works perfectly...so...just because your PSU is new, and doesn't appear to be faulty...that doesn't mean it isn't. And again, anything can go in your PC without warning, and there's a number of things that could be causing your problem, so more information is needed to narrow it down.