Thanks tons guys, I got it figured out.
I had a spare Ethernet card laying around. When I chucked it in everything was great! Internet and network speeds were back to normal. So, I guess it was just the onboard ethernet adapter that was screwed-up, right?
zENGER and whatthe, I didn't think it was the HD cuz everyother application I was running on the computer that weren't running online or on the server were running, copying, et cetera just fine. If all applications (both on and offline, networked and local) were running slow and freezing up in would probably be the loacl HD. Is that right?
Thanks again guys.