Hard Drive running fast

[new_novice]

I have a hp pavillion a750w and it seems on some web pages I browse on it revs up for a minute or two then

goes back to normal. What causes this?  Any help would be appreciated.

[GX1_Man]

Is it the hard drive or a fan? Open the case and isolate the sound origin. The hard drive is most likely not making the sound.

What kinds of pages do this? Does the computer work normally otherwise?