not sure exactly what category this falls under.
but this started as long as i can remember having this pc, about 2 years, i have had the same vid card since then an ati radeon 9800. i say that as i think thats the problem with the fan.
anyway it really only happens when im playing games. it used to just go tick really light and freeze everything for like half sec. which would halt all input like typing until it ended, usually only messing up a few letters. once i bought a soundblaster 5.1 card and a 5.1 speaker system it does it a lot louder sometimes a loud buzz like when u get snowy tv. other times just a double pop. and when it does this you can hear the fan inside either spinning faster or slowing back down.
it's very annoying and it only seems to do it 2-3 times per hour. on quake 4 when it happens it loses sound all together until i restart the game. :evil:
this is the reason i say its the video card because it only does it when the card is put to use. i don't have another card to test it with either. just hoping to see if anyone has ever had this problem or would know what to do besides buying a new card. it don't get in the way cept playing quake. also hoping maybe its a software issue, and i do have the newest drivers for sound and video.