Issues with Downloading

This is a difficult problem to explain so I ask that you please bare with me.

Internet on my desktop has become very choppy and it actually is preventing me from playing basically all online games, things get far too laggy, NPCs do not load, skills take a stupid amount of time to initiate and so on. I've made posts on other forums that were useless mostly, I believe people were confused by my explanation.

I have tried all the basics such as switching between wireless connections and wired connections, the problem still occurs. Online games and programs are mostly useless.

Time to throw you all off your thinking:
If I take 3 steps over to my laptop, this problem does not exist, everything runs flawlessly and I have download speeds of up to 40Mbps. Games run without stutter and without problems. This is on the same network and everything.

Again as a reminder: I have tried both a wireless and wired connection on my desktop
I've also tried updating ALL drivers, as well as restoring Windows 7 back to factory settings. I am at a complete loss.

I appreciate all help, if you require clarification or images, etc feel free to ask.

Thanks!