tom, are u using a tower or laptop...if it is a tower it is worth taking the side off and checking the cpu fan...i found mine was clogged with dust, fluff, doghair!! blow it out with an air compressor or can of compressed air or just use a soft paint brush to clear the fan...while you have it open it is worth peeling off the little sticker in the middle of the fan and putting a few drops of machine oil in..this will keep the fan quiet. Another problem can be a clogged power supply fan, this is the fan at the back of the tower..u can get at this by undoing a few screws...you have to get the power supply out and take the cover off to get to the fan...clean, oil and replace.....very quiet now!!!! and pc will run much much cooler.
OK, just read your post again...i see you are using a laptop...oh well, maybe this will help some one else.