One of your intertubes is gebust. Check the floor - do you have a bunch of packets all over the place? Even if you can't see them, they're there.
What I do, see, is get out the old Shop-Vac and run it all over the computer room. Then I put the hose into the computer and switch 'er over from suck to blow. You won't believe the difference that makes in your computer's performance.