Horrible internet connection?

[Shadohz]

If you have a router behind your modem/dsl then try disconnecting the router and plugging your PC directly to it. If the behavior is fixed then it could be a configuration problem with your router. You may need to disable logging or there's a configuration conflict with devices causing it to drop packets.

In an event like that back up the router configuration, reset the router then make minor changes to the router to see what triggered it. Also surge protectors are known to cause spike in modems and routers. Plug your devices directly to the wall socket. If the wall socket has a built-in surge protector then plug it to a wall socket that doesn't have one. If the power adapter of the device sits loose in the wall socket then push the prongs outward so the adapter seats correctly in the socket.

As your ISP to run network connection tests on your modem/dsl to confirm if there aren't issues on their end.

If the problem is on the PC side, then read this: http://www.wikihow.com/Speed-up-a-Slow-I...Connection
They are some of the most common issues I've come across fixing some people machines.