Okay, so here's the situation. We just upgraded our Trend Micro OfficeScan from v8.0 to v10.5. Before this upgrade, I was able to transfer data over our network, to my computer onto an external eSATA drive each day at about 10-40MB/S (higher 30's most of the time). After the upgrade, I now can only get about 1MB/S. Now, of course I thought this would come with the Real-Time Scanning feature of OfficeScan, so I disabled it. Nothing. And I still cannot figure out why this thing has taken such a decrease in performance with the only change being the OfficeScan upgrade.
As a note, I will be testing on another computer tomorrow to make sure that it's not just the that, or if it is, as one of the more simple tests after I configure the firewall. Ping results turned out fine, but I didn't expect it to have any issues there.
Thanks for the suggestions, and if I missed a tag or put it in the wrong place, I'll change it if I can.