Koolance Liquid Cooling system errors

Well, I have this computer someone asked me to fix because the graphics card wasn't working. I thought, "Hey, has to be simple. All I need to do is reseat it." So I did. No luck. Then, I go to a professor of mine's residence and ask him to take a look at it. He did the exact same thing I did, and it worked!!! (I don't know, lucky stuff happens sometime.)

Now, the only side effect (that has been happening ever since I got it) was that the stupid cooling system won't stop beeping when it's on. The error code (which I looked up online) was one of two things: first, it was sensor cable was in an open circuit, or second, the sensor was so-called short circuiting. So, I tried everything. I put some new thermal paste on there (it was dried out, so I thought the paste would make a better connection between the processor heatspread - I think that's what it's called - and the fan thing). I also tried looking up possible explanations online, but nothing was found.

The beeping is driving me nuts. The thing won't boot into VISTA (which I hate with passion) but I have concluded it is because of disk errors (which I will try to run chkdsk on).

Help?