CPU Spikes when Downloading

[spork]

I have this problem where when I'm downloading stuff (through bittorrent or whatever), I get these CPU spikes which causes stuttering. The System Process shoots up to 70-80% and then I get a stutter and the computer freezes a little. I notice this most when I'm playing a video or mp3 since the stutter is very obvious. But I don't think it's a sound card/video card problem because these spikes come up even when no sound is being played and no video usage other than desktop display/web display is being done.

This may happen when I'm not downloading anything but it's very rare in this case (though when it does happen when I'm not overtly downloading it's probably because something IS downloading in the background).

Any one have any ideas?

*Windows XP
*Athlon 2400
*512 MB DDR RAM
*Albatron KX400-8XV Mobo
*Western Digital HD (boot up drive)
*Hitachi HD
*Sound Blaster Live! (I think)
*Video card shouldn't matter since this was happening with my old my video card, I got a new one, happened with that, that one broke, put in a different old one and it still does it.
*Generic Ethernetcard
*USB Card in there but it's pretty much unused.

Thanks.

 

[Nodsu]

If it is really caused by network traffic then it may be your firewall software having trouble.

You should try to pinpoint the actual process that causes the slowdown. The simplest way is looking at the Windows Task Manager with the processes sorted by CPU usage.

 

[spork]

If it is really caused by network traffic then it may be your firewall software having trouble.

You should try to pinpoint the actual process that causes the slowdown. The simplest way is looking at the Windows Task Manager with the processes sorted by CPU usage.

Like I said in the first post, it's the "System" process that spikes. As in "System" for the image name and "SYSTEM" for the user name.

I don't think it's the network traffic as much as the writing to my hard drive that's the problem, but then again, I have no idea, hence me asking. Do you have any clues? It's not essential but it IS pretty annoying so I'd like to take care of that problem if all possible.

 

[Nodsu]

Looks to be some kernel issue then.
You could look at the Event Viewer to see some errors there maybe.
Could be a drivers issue too.
And of course failing hardware like bad sectors on the HD or errors on the (S)ATA channel.
How about a memory test and a hard drive diagnostics for starters?