Whenever i start my PC the video card fan makes a loud humming noise like it is being ran to fast.  This happened about a week after i installed the video card.  At first i though it was a defective video card so i sent the video card back.  Now I have installed the replacement video card and what do you know a week after install the fan is making a loud humming noise at startup, the noise goes away after windows is started.  I am using a dimension 8250, and windows XP.  This all started happening after i fried my video card about a month ago,  I didn't know what happened because my PC wouldn't start up.  So I called tech support and they told me that it was it might be my video card or mother board.  Well it ended up being the video card, but i think that something else has gone wrong. 

plz help if u can

thnx