To sniff out if it's hardware I boot up any of the Live OSes out there. But given only this much detail, well, any guess is likely wrong except for reloading the OS.
I'm currently running a Powerline Adapter connection from my router to my PC and I'm getting huge ping from it. These are the adapters: http://www.amazon.co.uk/TP-Link-TL-PA451KIT-Powerline-Adapter-Through/dp/B00D8BGLMY/ref=sr_1_5?ie=UTF8&qid=1420133078&sr=8-5&keywords=tp+link+500+powerline
Here is my speedtest.net
result. As you can see, 514ms is absolutely huge. I was sure it was my powerline adapters. I did everything under the sun with them (switching sockets, cable, etc etc) but it turns out that it's actually my PC. I should also add that at least once or twice a day my connection will drop completely for about a solid minute, windows "repair connection" finds nothing wrong. Something seems to be up with my PC.
A while ago I plugged my laptop in directly to my adapter instead of my PC and I got 14ms.
Anyone have any idea what could be causing this?
I did the following and it didn't change anything.
netsh winsock reset catalog
netsh int ipv4 reset reset.log
netsh int ipv6 reset reset.log